Ultimate Triple Berry Cake Recipe: Your Perfect Summer Dessert with Oat Crumble and Vanilla Cinnamon Buttercream

As the peak of summer brings glorious sunshine and rising temperatures, there’s nothing quite like a refreshing, flavorful dessert to help you cool down. This exquisite Triple Berry Cake is exactly what you need. Imagine layers of unbelievably light and fluffy vanilla cake, generously studded with a vibrant medley of fresh blueberries, raspberries, and blackberries. But that’s not all – this cake elevates the classic berry experience with a luscious triple berry compote, a delightfully crunchy oat crumble, and it’s all enrobed in a silky, aromatic vanilla cinnamon buttercream. It’s a symphony of textures and flavors that captures the very essence of summer.

If you’re searching for a spectacular dessert to grace your table this July, or any warm-weather gathering, look no further than this delightful Triple Berry Cake. We’ve taken the classic idea of a berry cake and given it a unique and unforgettable twist by incorporating an irresistible oat crumble. This addition doesn’t just add an extra layer of flavor; it introduces a wonderful, delicious crunchy texture that perfectly complements the soft cake and smooth frosting, ensuring every bite is a delightful experience. You and your guests will absolutely love this fresh, fruity, and flavorful creation.

For more sensational berry-inspired recipes, be sure to explore these tempting options:

Strawberry Cheesecake Cake

Easy and Delightful Blueberry Crisp Blondies

Delightful Lemon Blueberry Cake

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Why This Triple Berry Cake Recipe Is a Must-Try

This Triple Berry Cake isn’t just another dessert; it’s a carefully crafted experience designed to delight your senses. Here’s why this recipe truly shines and deserves a spot on your baking list:

• Perfectly Layered Cake: We’re talking about three magnificent layers of light, airy, and incredibly fluffy vanilla cake. What makes these layers truly special is the generous scattering of fresh, juicy berries baked right into the batter. This ensures a burst of fruity flavor with every tender forkful, making the cake moist, tender, and utterly delightful.
• A Trio of Flavorful Berries: Is a “triple berry threat” a thing? Because this cake certainly brings it! We harness the combined power of blueberries, raspberries, and blackberries to create a dynamic flavor profile. Blueberries offer sweet juiciness, raspberries provide a delicate tartness, and blackberries add a deeper, earthier note. Together, they create a balanced and utterly irresistible berry medley that sings of summer. You can use fresh berries during peak season for the best flavor, but frozen berries work beautifully too, making this cake enjoyable year-round.
• The Ultimate Summer Dessert: With berry season in full swing, there’s no better way to celebrate than with this show-stopping cake. Its light texture, vibrant fruit, and refreshing flavors make it the ideal centerpiece for barbecues, picnics, and any summer gathering. It’s not too heavy, offering a perfect sweet treat without weighing you down on a warm day.
• Irresistible Oat Crumble: This isn’t just a cake; it’s a “berry cobbler cake” reimagined! The homemade oat crumble is what truly pulls this cake together, adding an unexpected but utterly essential element. It’s infused with a hint of warm cinnamon and baked to a golden crisp, providing a fantastic contrast to the soft cake layers and smooth frosting. The crunchy texture and comforting spice notes elevate this cake from great to extraordinary, giving it that delightful “cobbler” feel.

Key Ingredients for Your Triple Berry Cake

To create this magnificent Triple Berry Cake, you’ll need a selection of fresh, high-quality ingredients. While the full list can be found in the detailed recipe card below, here’s a look at some of the essential components and why they matter:

• Unsalted Butter: For both the cake and buttercream, always opt for unsalted butter. This gives you complete control over the salt content in your recipe. For best results, ensure your butter is at room temperature for creaming, as this helps create a light and airy texture in the cake and a smooth buttercream.
• Cooking Spray: Though not an ingredient in the cake itself, a good quality cooking spray is crucial for preparing your cake pans. It ensures your beautiful cake layers release easily and perfectly, preventing any sticking disasters.
• Eggs: This recipe calls for a combination of whole eggs and egg whites (6 in total) to achieve that signature light and fluffy cake texture. Just like the butter, make sure your eggs are at room temperature. This allows them to emulsify properly with the other ingredients, creating a more uniform and tender crumb.
• Cake Flour: This is a secret weapon for achieving truly light, tender, and delicate cake layers. Cake flour has a lower protein content than all-purpose flour, which results in less gluten development and a softer cake. Spooning and leveling it correctly is key to accurate measurement.
• Clear Vanilla Extract: While any good vanilla extract works, clear vanilla extract is perfect for maintaining the pure white color of your vanilla cake layers and buttercream, especially when paired with vibrant berries. It adds that classic, comforting vanilla flavor.
• Buttermilk: Another essential for a tender and moist cake! Buttermilk reacts with the baking soda to give the cake its lift and contributes to its soft texture and slight tang, which beautifully complements the sweet berries. Remember to pull it out 2-4 hours before you start baking so it reaches room temperature.
• Fresh or Frozen Berries: The stars of our Triple Berry Cake! You’ll use a mix of blackberries, blueberries, and raspberries. Fresh berries, especially during their peak season, offer the best flavor and vibrant color. However, frozen berries are a fantastic alternative and can be used directly from the freezer; just be sure to toss them in a little flour before adding to the batter to prevent them from sinking to the bottom.
• Heavy Whipping Cream: This ingredient is vital for creating a rich, stable, and wonderfully creamy buttercream. Its high-fat content ensures a luxurious texture that pipes beautifully and holds its shape on the cake.

How to Make the Delicious Oat Crumble

The crunchy oat crumble adds a wonderful texture and a hint of cinnamon that makes this Triple Berry Cake truly unique. Follow these simple steps to create it:

1. Step 1: Preheat the oven and prep your pans. Begin by preheating your oven to 350°F (175°C). Line a standard cookie sheet with parchment paper. This will prevent the crumble from sticking and make cleanup a breeze. Set it aside for later.
2. Step 2: Mix the dry ingredients. In the bowl of a stand mixer, fitted with the paddle attachment, combine all of your dry crumble ingredients: old-fashioned oats, all-purpose flour, granulated sugar, brown sugar, cinnamon, and a pinch of salt. Mix on medium to low speed until everything is well combined and evenly distributed.
3. Step 3: Incorporate the butter. Add your softened unsalted butter to the dry mixture. Mix on low speed, allowing the butter to slowly combine with the dry ingredients until a crumbly, coarse mixture forms. You’ll see beautiful clusters that are perfect for baking.
4. Step 4: Bake to golden perfection. Spread the crumble mixture evenly across your prepped cookie sheet. Bake for approximately 5 minutes. Then, using a spatula, gently stir the mixture around to ensure even browning. Return it to the oven and bake for another 5 minutes, or until the crumble achieves a light golden-toasted color and is wonderfully fragrant.
5. Step 5: Cool and store. Once baked, remove the oat crumble from the oven and let it cool completely on the cookie sheet. As it cools, it will crisp up even further. Once fully cooled, transfer it to an airtight container. It can be stored at room temperature for up to 5 days, ready to be assembled into your stunning Triple Berry Cake.

Crafting the Fluffy Vanilla Berry Cake Layers

These light and airy vanilla cake layers, generously dotted with berries, form the delicious foundation of our Triple Berry Cake. Precision and room temperature ingredients are key for success here.

1. Step 1: Prepare your pans. Preheat your oven to 325°F (160°C). Prepare three 8-inch or four 6-inch round cake pans by spraying them thoroughly with cooking spray. For extra assurance, line the bottoms of the pans with parchment paper circles and spray again. This ensures your cake layers release without a hitch. Set them aside.
2. Step 2: Combine the dry ingredients. In a medium-sized bowl, whisk together the cake flour, baking powder, baking soda, and salt. Whisk well to ensure all leavening agents are evenly distributed. Set this dry mixture aside.
3. Step 3: Cream the butter and sugar. In the bowl of a stand mixer fitted with the paddle attachment, combine the room temperature unsalted butter, vegetable oil, and granulated sugar. Beat on high speed for approximately 4 minutes, until the mixture becomes light, fluffy, and smooth. This step is crucial for incorporating air, which contributes to the cake’s tender crumb.
4. Step 4: Add eggs, egg whites, and flavorings. With the mixer running on medium speed, gradually add the large whole egg and the five large egg whites, one at a time. After each addition, pause to scrape down the sides and bottom of the bowl, ensuring everything is fully incorporated. Once all eggs are added, beat on medium speed for 1 minute. Next, add the room temperature sour cream and clear vanilla extract, beating on medium speed for another 30 seconds until just combined.
5. Step 5: Alternate dry and wet ingredients. Reduce the mixer speed to low. Add half of the dry flour mixture to the butter mixture, mixing until just incorporated. Then, add half of the room temperature buttermilk and mix until combined. Repeat this process with the remaining flour mixture and buttermilk, mixing on low speed only until the batter is smooth and no streaks of flour remain. Be careful not to overmix, as this can lead to a tough cake.
6. Step 6: Fold in the fresh berries. Using a rubber spatula, gently fold in the mixed berries that have been lightly coated in a quarter cup of flour. The flour coating helps prevent the berries from sinking to the bottom of the cake layers during baking.
7. Step 7: Divide and bake. For consistent and even layers, use a kitchen scale to evenly distribute the cake batter among your prepared pans. Aim for about 18 ounces (approx. 510g) per 8-inch pan or 12 ounces (approx. 340g) per 6-inch pan. Bake for 25-30 minutes, or until a wooden toothpick inserted into the center comes out with just a few moist crumbs attached, or until the tops are lightly golden brown and spring back when gently pressed.
8. Step 8: Cool the cake layers. Once baked, remove the cakes from the oven and allow them to cool in their pans for about 15 minutes. This helps them firm up before handling. After 15 minutes, carefully invert them onto cooling racks to cool completely. Once fully cooled, wrap each cake layer individually in plastic wrap and store them in the refrigerator or freezer until you’re ready to frost. If your cakes have a slight dome, level them once cooled but before chilling.

Creating the Luscious Triple Berry Compote

This vibrant triple berry compote is the juicy heart of our cake, adding a burst of concentrated berry flavor and a beautiful texture. Making it is easier than you think!

1. Step 1: Cook the berries. In a small saucepan over medium heat, combine your mixed berries (blueberries, raspberries, blackberries), sugar, and water. Stir gently until all ingredients are combined. Allow the mixture to simmer, stirring occasionally, until the berries begin to soften and break open, releasing their juices, and the mixture thickens to a sauce-like consistency.
2. Step 2: Thicken with a cornstarch slurry. While the compote is still hot and bubbling, prepare a cornstarch slurry by whisking together cornstarch with a small amount of cold water until smooth. Pour this slurry into the hot berry mixture, stirring constantly. The heat will activate the cornstarch, causing the compote to thicken. Initially, the mixture might appear a lighter purple; continue to cook and stir until the color deepens, which indicates that the cornstarch flavor is cooking out.
3. Step 3: Cool for perfect consistency. Remove the compote from the heat and set it aside to cool to room temperature. As it cools, it will continue to thicken, achieving that perfect jam-like consistency. To prevent a “skin” from forming on the surface, press a piece of plastic wrap directly onto the top of the compote. If desired, you can place it in the refrigerator to speed up the cooling process, ensuring it’s firm and ready for cake assembly.

Perfecting the Vanilla Cinnamon Buttercream

The rich and flavorful vanilla cinnamon buttercream is the crowning glory of this Triple Berry Cake. Its smooth texture and warm spice notes perfectly complement the fresh berries. Here’s how to achieve perfection:

1. Step 1: Beat the butter. In the bowl of a stand mixer fitted with a paddle attachment, cream the slightly chilled unsalted butter on medium speed for about 2 minutes. This incorporates air and makes the butter light and fluffy. Don’t forget to stop and scrape down the sides of the bowl with a rubber spatula to ensure even mixing.
2. Step 2: Add powdered sugar. Gradually add the sifted powdered sugar to the creamed butter. Start mixing on a low speed to avoid a sugar cloud, increasing the speed slightly until it’s just incorporated. Scrape down the sides and bottom of the bowl thoroughly again to catch any unmixed sugar.
3. Step 3: Incorporate remaining ingredients. Turn the mixer to medium speed and add the heavy whipping cream, vanilla bean paste (or extract), ground cinnamon, and a pinch of salt. Mix until just combined.
4. Step 4: Beat for lightness. Increase the mixer speed to medium-high and beat the buttercream for an additional 5 minutes. During this time, the frosting will visibly lighten in both color and texture, becoming incredibly smooth, airy, and spreadable.
5. Step 5: Create a berry-infused buttercream (optional). For an extra layer of berry flavor and a beautiful pink hue, take about two cups of the finished vanilla buttercream and place it in a small bowl. Add about ¼ cup of your prepared triple berry compote. Gently mix with a rubber spatula until the compote is swirled throughout the buttercream. Set this aside for the filling.
6. Step 6: Remove air pockets. Before you begin frosting your cake, take a wooden spoon or rubber spatula and vigorously mix the buttercream by hand for a couple of minutes. This vital step helps to push out any excess air pockets, resulting in an incredibly smooth, lump-free frosting that’s a dream to work with.

Assembling Your Masterpiece: The Triple Berry Cake

Now comes the exciting part – bringing all the components of your Triple Berry Cake together to create a stunning and delicious dessert. Follow these steps for a beautifully layered cake:

• Secure the first layer: Pipe a small dollop of your vanilla cinnamon buttercream onto the center of a cake board or serving plate. This acts as a “glue” to prevent your cake from sliding. Carefully place your first cooled cake layer, top side up, onto the frosting.
• Apply berry buttercream: Take half of the triple berry buttercream (if you made it) or your vanilla cinnamon buttercream, and spread it evenly across the surface of the first cake layer, extending all the way to the edges.
• Create a frosting dam and add compote: Using a piping bag or a spoon, pipe an extra rim of the plain vanilla cinnamon buttercream around the very edge of the frosted cake layer. This “dam” will act as a barrier to hold the berry compote securely in place and prevent it from spilling out. Then, spread about ⅓ cup of your prepared triple berry compote within this dam. Remember, don’t overfill with compote; you can always serve extra on the side!
• Add the oat crumble: Generously sprinkle about half of your crunchy oat crumble evenly over the berry compote layer. This adds that fantastic texture contrast.
• Repeat for the second layer: Gently place the second cake layer on top of the filling and crumble. Repeat the process: frost with the remaining berry buttercream (or vanilla cinnamon buttercream), create a frosting dam, spread the remaining ⅓ cup of berry filling, and sprinkle with the remaining oat crumble.
• Place the final layer: Carefully place the final cake layer on top of the second filling layer, this time placing it top side down. This helps create a flatter, more stable top surface for frosting.
• Apply a crumb coat: Using a small amount of your plain vanilla cinnamon buttercream, apply a very thin layer all around the entire cake – top and sides. This is called a crumb coat, and its purpose is to trap any loose crumbs, preventing them from mixing into your final decorative layer of frosting. Freeze the cake for about 10-15 minutes to allow this crumb coat to set firmly.
• Final frosting and decoration: Once the crumb coat is firm and “locked in,” remove the cake from the freezer. Use the remaining vanilla cinnamon buttercream to finish frosting and decorating your cake. Use an offset spatula or a cake scraper to achieve smooth sides and a clean top. Garnish with extra fresh berries and a sprinkle of any leftover oat crumble for a beautiful presentation.

Expert Tips for a Perfect Triple Berry Cake Every Time

Achieving a truly professional and delicious Triple Berry Cake is easier with a few insider tricks. These expert baking tips will help you create a show-stopping dessert that tastes as good as it looks:

1. Thoroughly Cream Butter and Sugar: I cannot emphasize this enough! When making your cake batter, dedicating ample time to creaming the butter, oil, and sugar together until they are light, fluffy, and almost white is absolutely crucial. This process incorporates tiny air pockets into the mixture, which are essential for the cake layers to rise beautifully and achieve that incredibly light and tender texture we’re aiming for. Don’t rush this step!
2. Invest in High-Quality Cake Pans: The quality of your cake pans makes a significant difference in the final product. High-quality pans, especially those made from anodized aluminum, ensure even heat distribution. This prevents your cake layers from browning too quickly or unevenly on the sides and bottom, giving you perfectly golden, uniformly baked cakes. I always recommend and use Fat Daddio’s cake pans; you can find the ones I use here.
3. Always Use Room Temperature Ingredients: This is a golden rule in baking, and for good reason! Ensuring all your cold ingredients (butter, eggs, buttermilk, sour cream) are at the same room temperature before mixing is a must. This allows them to emulsify properly, creating a smooth, cohesive batter that traps air more effectively and bakes more evenly, resulting in a perfectly textured cake. Plan ahead and pull them out a few hours before you start.
4. Achieve Creamy, Smooth Buttercream: For that picture-perfect, silky smooth buttercream, here’s a trick: once you’ve finished mixing your buttercream with the stand mixer, add a tablespoon or two of heavy whipping cream. Then, using a sturdy wooden spoon or a rubber spatula, vigorously beat the buttercream by hand for a couple of minutes. This technique effectively pushes out any tiny air bubbles that the mixer may have incorporated, leaving you with an incredibly smooth, professional-looking frosting.
5. Don’t Skip the Crumb Coat: This step is simple but incredibly important for a clean, professional finish. Applying a thin layer of frosting (the crumb coat) to your entire cake and then chilling it helps to lock down any loose crumbs. This prevents them from migrating into your final layer of frosting, ensuring your cake looks perfectly neat and polished.
6. Utilize a Turntable for Easy Decoration: A revolving cake stand, or turntable, is an invaluable tool for decorating layered cakes like our Triple Berry Cake. It allows you to easily rotate the cake as you apply frosting, smooth the sides, and add decorations, making the process much more efficient and helping you achieve a flawless finish with minimal effort. You can find the one I use here.
7. Master with an Offset Spatula: An offset spatula is your best friend when it comes to frosting cakes. Its angled blade makes it incredibly easy to spread buttercream smoothly and evenly over the top and sides of your cake layers, creating sharp edges and a clean surface. It provides better leverage and control than a straight spatula. You can find my preferred offset spatula here (add link).

Storing Your Triple Berry Cake for Optimal Freshness

Proper storage is key to enjoying your delicious Triple Berry Cake for as long as possible. Here’s how to keep each component fresh, whether you’re baking in stages or after assembly:

• Cake Layers: If you’re dividing your cake-making into multiple days (which is a great time-saver!), bake your cake layers ahead of time. Once they are completely cooled, individually wrap each cake layer tightly with plastic wrap. You can then store them in the refrigerator for 3-5 days, or in the freezer for up to 2 months. Freezing them helps to lock in moisture and also makes them firmer and easier to handle, reducing crumbs and preventing layers from sliding around during assembly and decorating. Thaw frozen layers in the refrigerator overnight before use.
• Triple Berry Compote: The berry compote is best made on the same day you plan to stack and assemble your cake. While it can be made a day in advance, it tends to lose some of its vibrant fresh flavor and may not hold its consistency as well over extended periods. Once made, allow it to cool completely to room temperature, then transfer it to an airtight container and store it in the refrigerator. This will keep it cold and stable, ready to be spread between your cake layers.
• Oat Crumble: Your crunchy oat crumble is quite sturdy! Once completely cooled after baking, transfer it to an airtight container. It can be stored at room temperature for up to 5 days. If you prefer to keep it extra crisp, you can store it in the refrigerator.
• Assembled Cake: Once the Triple Berry Cake is fully assembled and frosted, it should be stored in an airtight cake carrier or under a cake dome in the refrigerator. This will keep the buttercream firm and prevent the cake from drying out. It will stay fresh for 3-4 days. For optimal flavor and texture, allow the cake to come to room temperature for about 30 minutes before serving.

Here are some other cake recipes you are going to love:

Recipe

Triple Berry Cake

Molly Murphy

This cake features light and fluffy vanilla cake layers infused with fresh blueberries, raspberries, and blackberries. It’s enhanced with a delightful triple berry compote and a crunchy oat crumble, all frosted in a luscious vanilla cinnamon buttercream.

5 from 5 votes

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Course
Dessert

Cuisine
Cake

Ingredients

For the oatmeal crumble

• ½ cup butter softened
• 1 cup old fashioned oats
• 1 cup all-purpose flour
• ¼ cup granulated sugar
• ½ cup brown sugar
• ½ teaspoon cinnamon
• Pinch of salt

For the cake

• 1 cup unsalted butter room temperature
• 1¾ cups granulated sugar
• 2 Tablespoons vegetable oil
• 1 large whole egg room temperature
• 5 large egg whites room temperature
• ¼ cup sour cream room temperature
• 1 Tablespoon clear vanilla extract
• 3 cups cake flour spooned and leveled
• 1 Tablespoon baking powder
• ½ teaspoon baking soda
• 1 teaspoon salt
• 1¼ cups buttermilk room temperature
• 1½ cup fresh berries tossed in about ¼ cup flour to evenly coat (I use blackberries raspberries, and blueberries).

Berry Compote

• 1½ cup mixed berries ½ cup of raspberries, ½ cup blueberries, ½ cup blackberries
• 1 Tablespoon lemon juice
• ¼ cup sugar
• ¾ cup water
• 2 Tablespoons cornstarch

For the buttercream

• 2 cups unsalted butter slightly chilled
• 5 ½ cups powdered sugar measured and then sifted
• ¼ cup heavy whipping cream
• 3 teaspoons vanilla bean paste
• 2 teaspoons ground cinnamon
• Pinch of salt

Instructions

For the crumble

• Preheat the oven to 350 degrees F (175 C). Line a cookie sheet with parchment paper. Set aside. In the bowl of a stand mixer fitted with the paddle attachment, on medium to low speed, mix together all of the ingredients except for the butter.
• Add in the softened butter and mix on low until everything is combined and forms a crumbly mixture.
• Spread the mixture on the prepped cookie sheet. Bake for about 5 minutes, then with a spatula, stir the mixture around and bake for another 5 minutes, or until the crumble has a light toasted color and is fragrant.
• Let it cool completely. Once cooled, store in an airtight container until you’re ready to assemble your cake. It can be stored at room temperature for up to 5 days.

For the cake

• Preheat your oven to 325 degrees F (160 C). Spray three 8-inch or four 6-inch round cake pans with cooking spray. Spray the bottom of the pans, line the bottoms with parchment paper, and spray again. Set aside.
• In a medium sized bowl, whisk together the cake flour, baking soda, baking powder, and salt. Set aside.
• In the bowl of a stand mixer fitted with the paddle attachment, beat the room temperature butter, oil, and granulated sugar on high until light, fluffy, and smooth, about 4 minutes.
• With the mixer on medium speed, start adding the large whole egg and the egg whites, one at a time, to the bowl, scraping the bottom and the sides of the bowl between each addition. After all the eggs have been added, beat on medium speed for 1 minute. Add the room temperature sour cream and clear vanilla extract. Beat on medium speed for 30 seconds.
• Turn the mixer on low and add half of the flour mixture and half of the room temperature buttermilk to the butter mixture and mix until fully incorporated. Finally, add the rest of the flour mixture and the rest of the buttermilk, mixing on low speed until just combined. Do not overmix.
• With a rubber spatula, gently fold in the mixed berries that have been coated in flour.
• Using a kitchen scale, evenly distribute the cake batter among the three 8-inch or four 6-inch pans (about 18 ounces in the 8 inch, and 12 ounces in the 6 inch) and bake for 25-30 minutes, or until a toothpick inserted into the center comes out with just a few moist crumbs on it or until it starts to get a little golden brown on top.
• Remove cakes from the oven and let them cool in their pans for 15 minutes before taking them out of the pans and placing them on cooling racks to cool completely.
• When the cakes are completely cooled, wrap each cake layer individually with plastic wrap and store it in the refrigerator or freezer until you’re ready to frost.
• If your cakes have a small dome, level them when they are cool, but before you place them in the fridge.

For the berry compote

• In a small saucepan over medium heat, combine all the berries, sugar, and water. Stir until combined. Let it continue cooking until the berries start to open and the mixture reaches a sauce consistency.
• Make a slurry by combining the water and the cornstarch. Ensure your berry compote is still hot and bubbling, then add the slurry (the heat helps activate the cornstarch). Stir continuously until it starts to thicken. When you first add the slurry, it will be a light purple. Continue to cook and stir until it darkens in color, which means you are cooking out the flavor of the cornstarch.
• Remove from heat and set aside to let it come to room temperature. As it cools down, it will thicken even more. Press plastic wrap directly on the top surface to help prevent a skin from forming.
• You can put it in the fridge, if you desire, to speed up the cooling process.

For the buttercream

• In the bowl of a stand mixer fitted with a paddle attachment, cream the slightly chilled butter for about 2 minutes on medium speed until light and fluffy. Scrape down the sides with a rubber spatula.
• Add the sifted powdered sugar gradually and mix on low speed just until incorporated. Scrape down the sides and bottom of the bowl again.
• Turn the mixer to medium speed and add the heavy whipping cream, vanilla bean paste, ground cinnamon, and a pinch of salt. Mix until combined.
• Turn the mixer to medium-high speed and beat for an additional 5 minutes. The frosting will become noticeably lighter in color and texture, becoming smooth and airy.
• In a small bowl, add two cups of the vanilla buttercream and about ¼ cup of the triple berry compote. Mix with a rubber spatula to create a berry-swirled buttercream. Set aside.
• Before spreading the frosting on your cake, spend a couple of minutes mixing the buttercream by hand with a wooden spoon or a rubber spatula to push out any air pockets, resulting in a smoother application.

Assembly

• Pipe a small dollop of frosting onto the middle of a cake board or serving plate to act as a glue and hold the cake in place. Place the first cake layer, top side up, on the cake board.
• Add half of the triple berry buttercream (or vanilla cinnamon buttercream) and evenly apply it to the edges of the cake.
• Pipe an extra rim of the plain vanilla cinnamon frosting around the edge of the frosted layer. This will help support the cake layers and prevent the berry filling from spilling out. Spread about ⅓ cup of the berry filling on the cake layer within the dam. Note: Don’t overfill with the compote. You can always serve extra on the side.
• Sprinkle about half of the prepared oat crumble evenly over the berry compote.
• Gently place the second cake layer on top of the filling/crumble and repeat the same process for the second cake layer (frosting, dam, compote, crumble).
• Place the final cake layer, top side down, on the second layer of filling.
• Apply a small amount of the plain vanilla cinnamon frosting around the entire cake to act as a crumb coat. Freeze the cake for 10-15 minutes to allow the crumb coat to set firmly.
• After the crumbs are locked in, continue to frost and decorate the cake with the rest of the buttercream for a smooth, finished look.

Keyword
berries, triple berry, summer cake, cobbler cake, vanilla berry cake

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