Decadent Chocolate Peanut Butter Marshmallow Snack Cake: Your New Favorite Indulgence

Prepare to delight your taste buds with our sensational **Chocolate Peanut Butter Marshmallow Snack Cake**. This extraordinary dessert is a harmonious blend of rich dark chocolate cake, a luscious and smooth peanut butter frosting, and a cloud-like homemade marshmallow fluff. It’s an unforgettable treat that combines three beloved flavors into one perfect bite, offering a nostalgic and deeply satisfying experience for any dessert lover.

Don’t let its humble “snack cake” title fool you – this dessert, while modest in size, delivers an explosion of flavor that rivals any grand celebration cake. Designed to serve a small gathering or provide a few days of delightful treats, this recipe is also incredibly versatile and can be effortlessly doubled to cater to a much larger crowd. It’s the perfect solution for those moments when you crave something special without the fuss of a multi-tiered masterpiece. Every forkful offers a nostalgic journey through the classic trio of rich chocolate, savory peanut butter, and sweet, airy marshmallow. This cake is truly the ultimate comfort food, elevated.

Discover More Chocolate and Peanut Butter Delights

If you’re a chocolate and peanut butter enthusiast like us, you’ll surely enjoy these other delectable recipes from our collection:

• Classic Chocolate Cake With Peanut Butter Frosting
• Delectable and Easy Oreo Peanut Butter Cake
• Effortless One Bowl Peanut Butter Oreo Bars

Why You’ll Love Making This Chocolate Peanut Butter Marshmallow Cake

This isn’t just another cake recipe; it’s an invitation to create something truly special and satisfying. Here’s why this Chocolate Peanut Butter Marshmallow Snack Cake will quickly become a cherished favorite in your baking repertoire:

• Unbelievably Moist Dark Chocolate Cake: Forget dry, crumbly cakes! This recipe guarantees a supremely moist and tender dark chocolate cake base infused with rich, intense cocoa. The deep chocolate flavor provides the perfect counterpoint to the sweetness of the frosting and fluff, creating a truly balanced and luxurious taste experience. Its fine, velvety crumb will have everyone asking for your secret.
• Effortlessly Easy to Bake: Don’t be intimidated by the impressive layers! This cake is designed for simplicity. With straightforward steps and minimal fuss, you’ll find that mixing the wet and dry ingredients comes together quickly, making it a fantastic option for bakers of all skill levels. It’s so forgiving, it’s genuinely hard to mess up, ensuring a successful bake every single time, even for beginner bakers.
• Velvety Smooth Peanut Butter Buttercream: The star of the middle layer is this unbelievably creamy peanut butter frosting. Crafted with smooth, high-quality peanut butter (we highly recommend a creamy brand like Skippy for its consistent texture and rich, slightly salty flavor), this buttercream adds a savory, nutty depth that perfectly complements the chocolate. Its smooth consistency makes it a dream to spread, creating a delightful and balanced interface between the cake and the marshmallow.
• Light and Airy Homemade Marshmallow Fluff: The crowning glory of this cake is the ethereal marshmallow fluff. Whether you opt for a quick store-bought jar (a perfectly acceptable shortcut for busy bakers!) or decide to whip up your own from scratch for an extra touch of pride, this fluffy topping adds a unique sweetness and an incredibly light, airy texture that elevates the entire dessert. It’s the perfect sweet cloud to finish off this masterpiece, making each bite feel indulgent.
• Perfectly Portioned Snack Cake: Made in a convenient 8×8 or 9×9 inch pan, this cake is ideal for smaller gatherings, intimate family dessert nights, or simply when you want a treat without committing to a giant, multi-layered cake. It’s the ultimate “snack cake” – substantial enough to satisfy your craving, yet perfectly sized to avoid overwhelming leftovers. Its manageable dimensions also make baking a breeze and cooling times quicker.

Essential Ingredients for Your Chocolate Peanut Butter Marshmallow Cake

Crafting this delicious cake starts with understanding the role of each ingredient. Here’s a breakdown of what you’ll need and why each component is crucial for achieving the perfect flavor and texture:

• Premium Dark Cocoa Powder: This is the heart of your rich chocolate cake. Using a high-quality dark cocoa powder (like the one you can find here) ensures a deep, intense chocolate flavor that isn’t overly sweet. It’s crucial for achieving that signature dark cake profile and a striking contrast with the lighter toppings.
• Fresh Baking Powder & Baking Soda: These leavening agents are the secret to a beautifully risen, light, and airy cake. Always ensure your baking powder and baking soda are fresh (we recommend replacing them every 3-6 months) to guarantee maximum effectiveness and a perfectly textured cake with a tender crumb. This ensures a consistent and impressive rise every time.
• Room Temperature Eggs: A non-negotiable for superior baking results! Eggs at room temperature emulsify better with other ingredients, creating a smoother, more uniform batter. This leads to a more consistent crumb structure and a more tender, moist cake. Simply take them out of the fridge a couple of hours before you plan to bake, or quickly warm them in a bowl of warm water for 10-15 minutes.
• Hot Water: This seemingly simple ingredient plays a vital role in “blooming” the cocoa powder. Mixing hot water with cocoa powder intensifies its flavor, giving your chocolate cake an even deeper and richer taste profile. It also contributes to the cake’s moistness and helps create a thin, pourable batter.
• Heavy Cream: Essential for achieving that irresistibly creamy and smooth peanut butter buttercream. Without heavy cream, your frosting can turn out dry, crumbly, and stiff. It adds richness and helps create a luxurious, spreadable consistency that melts in your mouth, making your frosting truly decadent.
• Smooth Peanut Butter: For the ultimate creamy frosting, smooth peanut butter is key. We highly recommend using a commercial brand like Skippy for its consistent texture and rich, sweet, and slightly salty flavor profile, which is perfect for balancing the cake’s sweetness. Avoid natural peanut butter with excessive oil separation as it can affect the frosting’s consistency.
• Corn Syrup (for Homemade Marshmallow Fluff): If you’re making your marshmallow fluff from scratch, light corn syrup is a crucial ingredient. It helps prevent sugar crystallization, ensuring a silky-smooth, stable, and glossy marshmallow. If you prefer convenience and time-saving, a small jar of store-bought marshmallow fluff works wonderfully and is a perfectly acceptable shortcut!
• Buttermilk: Adds a tender crumb and a subtle tang to the chocolate cake, enhancing its overall flavor and moistness. The acidity in buttermilk also reacts with baking soda, aiding in leavening. If you don’t have buttermilk on hand, you can easily make your own by adding a tablespoon of lemon juice or white vinegar to regular milk and letting it sit for 5-10 minutes until it slightly curdles.
• Vegetable Oil: Contributes significantly to the cake’s incredible moistness and helps keep it tender for days. Unlike butter, oil remains liquid at room temperature, making the cake crumb incredibly soft and rich.
• Granulated Sugar & Pure Vanilla Extract: These are standard baking staples that provide the necessary sweetness and enhance all the other flavors, making the chocolate and peanut butter truly sing. Always opt for pure vanilla extract for the best, most authentic flavor profile in both the cake and the frosting.

Step-by-Step Guide to Baking Your Perfect Snack Cake

Follow these detailed instructions to create your delicious Chocolate Peanut Butter Marshmallow Cake. While a stand mixer (like a KitchenAid) makes the process incredibly easy and efficient, you can absolutely achieve fantastic results with two large mixing bowls and a sturdy whisk! The key is careful measurement, attention to detail, and gentle mixing at each stage.

Part 1: Crafting the Moist Dark Chocolate Cake

1. Step 1: Prepare Your Baking Environment. Begin by preheating your oven to a precise 325°F (160°C). This slightly lower temperature helps ensure a moist cake that bakes evenly without drying out the edges. Next, take an 8×8 or 9×9 inch square cake pan and generously spray it with a non-stick cooking spray. For effortless removal, line the bottom with a piece of parchment paper, allowing some overhang for “handles,” then spray the parchment paper again. This double layer of protection ensures your beautiful cake won’t stick, making transfer a breeze. Set the prepped pan aside.
2. Step 2: Combine the Dry Ingredients. In the bowl of your stand mixer, fitted with the paddle attachment (or a large mixing bowl if hand-mixing with a whisk), add your all-purpose flour, granulated sugar, dark cocoa powder, baking soda, baking powder, and salt. Mix these dry ingredients on the lowest speed for about 30 seconds, or until they are thoroughly and evenly combined. This crucial step ensures that all the leavening agents and flavorings are well-distributed throughout the cake batter, preventing pockets of unmixed ingredients.
3. Step 3: Whisk Together the Wet Ingredients. In a separate, medium-sized bowl, whisk together your room temperature eggs, buttermilk, hot water, pure vanilla extract, and vegetable oil until the mixture is completely homogenous. There should be no visible streaks of egg yolk or oil. The hot water will already begin to “bloom” the cocoa powder in the dry mix, enhancing the chocolate flavor even further.
4. Step 4: Gently Incorporate Wet into Dry. With your stand mixer still on the lowest speed, slowly pour the liquid ingredients into the dry ingredients. Mix just until combined, being careful not to overmix. It’s crucial to stop as soon as you no longer see any visible streaks of flour; overmixing develops gluten, which can lead to a tough, dry cake. Finish by using a sturdy rubber spatula to scrape down the sides and bottom of the bowl, ensuring all ingredients are fully incorporated and the batter is smooth.
5. Step 5: Pour and Bake to Perfection. Carefully pour the cake batter into your prepared 8×8 or 9×9 inch pan. Gently smooth the top of the batter with a small offset spatula to ensure even baking and a level surface. Transfer the pan to your preheated oven and bake for approximately 35-40 minutes. The exact baking time can vary depending on your oven, so begin checking for doneness around 30-35 minutes. The cake is done when a toothpick inserted into the center comes out clean or with only a few moist crumbs attached.
6. Step 6: Cool Down. Once baked, remove the cake from the oven and let it cool in the pan on a wire rack for about 10-15 minutes. This initial cooling period allows the cake to set and firm up slightly. After 10-15 minutes, carefully lift the cake out of the pan using the parchment paper overhang and transfer it directly onto the wire rack to cool completely. For quicker cooling (essential before frosting), you can transfer it to the fridge for 30 minutes or the freezer for 20 minutes while you prepare the frosting and marshmallow fluff. A completely cool cake is crucial to prevent your delicious frosting from melting.

Part 2: Preparing the Creamy Peanut Butter Buttercream

1. Step 1: Cream Butter and Peanut Butter. In the bowl of an electric mixer fitted with the paddle attachment, combine the softened, room temperature unsalted butter and creamy peanut butter. Beat on medium-high speed for about 2 minutes until the mixture is light, fluffy, and perfectly smooth. This aeration is key for a light, airy buttercream.
2. Step 2: Incorporate Powdered Sugar and Liquids. With the mixer on the lowest speed, gradually add the sifted powdered sugar, pure vanilla extract, and a pinch of salt to the butter mixture. Start with 2 tablespoons of heavy cream. Once the ingredients are mostly combined (it may look crumbly at first), increase the speed to high and beat for 3 minutes. Stop, scrape down the sides of the bowl with a spatula, and beat for another 1 minute. If the frosting seems too stiff, add the remaining tablespoon of heavy cream, one teaspoon at a time, until it reaches a wonderfully light and fluffy consistency.
3. Step 3: Eliminate Air Bubbles for a Silky Finish. For an exceptionally smooth and silky buttercream, remove the bowl from the mixer and, using a sturdy rubber spatula or wooden spoon, vigorously stir and press the frosting by hand against the sides of the bowl for several minutes. This technique helps to push out any trapped air bubbles, resulting in a dense, velvety-smooth frosting that’s a dream to spread and looks incredibly professional on your cake.

Part 3: Crafting the Homemade Marshmallow Fluff (Optional)

If you prefer to make your own marshmallow fluff for an extra fresh taste, follow these steps. Otherwise, a 7-ounce jar of store-bought marshmallow fluff works perfectly and saves time!

1. Step 1: Prepare Egg Whites. In the clean bowl of a standing mixer, add two room temperature egg whites and a pinch of salt. Using the whisk attachment, beat on low speed until the egg whites become frothy and slightly bubbly. Keep the mixer on the lowest speed to maintain stability while you prepare the hot sugar syrup.
2. Step 2: Cook the Sugar Syrup. In a small, heavy-bottomed saucepan, combine 3 tablespoons of granulated sugar, ½ cup of light corn syrup, and 2 tablespoons (29.6g) of water. Place over medium heat and stir constantly until the sugar has completely dissolved, which typically takes about 3-5 minutes. You’re not looking for a specific temperature, just for the sugar to be fully incorporated into the syrup and the mixture to be hot. Remove from heat immediately once dissolved and add 1 teaspoon vanilla extract.
3. Step 3: Temper the Egg Whites. With the mixer on medium-high speed, very slowly and carefully pour the hot sugar syrup in a thin, steady stream down the inside rim of the mixing bowl. This gradual pouring is crucial for tempering the egg whites, effectively cooking them with the hot syrup and preventing them from scrambling. This process should take about 2 minutes. Continue mixing until all the syrup is incorporated.
4. Step 4: Whip to Stiff Peaks. Once all the sugar syrup has been added, increase the mixer speed to high and continue to beat for about 5 minutes, or until the marshmallow fluff is very stiff, glossy, and holds firm peaks. It will transform into a thick, shiny, and wonderfully fluffy consistency. Note: Homemade marshmallow fluff is best made and used the day it’s created for optimal texture, as it tends to lose some of its airiness over extended periods.

Part 4: Assembling Your Masterpiece

1. Step 1: Frost with Peanut Butter Buttercream. Ensure your chocolate cake is completely cool or chilled. Using your prepared peanut butter frosting, generously spread an even layer over the top of the cake. For even distribution, a helpful trick is to use a large cookie scoop to place 9 dollops of frosting across the cake’s surface, then gently spread them out with a small offset spatula. This method helps ensure every slice gets a perfect amount of frosting and a smooth, appealing layer.
2. Step 2: Top with Marshmallow Fluff. Next, spoon the marshmallow fluff over the peanut butter frosting. Gently and evenly spread it across the entire surface using your offset spatula. You might not use all of your homemade marshmallow fluff; any leftover can be stored in an airtight container or plastic bag and frozen for up to 3 months for another delicious use in hot cocoa or on crackers!
3. Step 3: Slice and Serve! Once assembled, allow the cake to set for a few minutes (this helps the layers settle). Then, with a sharp, clean knife (wiping it between cuts for a cleaner slice), cut your Chocolate Peanut Butter Marshmallow Snack Cake into 9, 12, or even 16 pieces, depending on your desired serving size. Serve at room temperature for the best flavor and texture experience, allowing the frosting and cake to soften slightly.

Expert Baking Tips for Your Best Snack Cake Yet

Achieving baking perfection often comes down to a few key techniques and habits. Incorporate these expert tips into your process for a consistently delicious and beautiful Chocolate Peanut Butter Marshmallow Snack Cake:

1. Invest in High-Quality Cake Pans: The right tools make all the difference. Using good quality cake pans, such as those from USA Pans, helps distribute heat evenly across the entire surface. This prevents your cake layers from browning too much on the sides or baking unevenly, resulting in a perfectly tender crumb from edge to center. High-quality pans also tend to be non-stick and release cakes much more easily.
2. Always Use Room Temperature Ingredients: This tip is mentioned often for a reason – it’s a genuine game-changer! Ensuring all your cold ingredients (eggs, buttermilk, butter) are at room temperature is absolutely crucial. Room temperature ingredients emulsify much more effectively, creating a smoother, more homogenous batter and frosting. This leads to a more consistent crumb structure, a better rise, and a creamier, lighter buttercream. Plan ahead and pull them out of the fridge an hour or two before you start baking, or use quick-warming methods.
3. Achieve Silky Smooth Buttercream: After whipping your peanut butter buttercream in the mixer, for an exceptionally creamy and smooth texture free of air bubbles, transfer the frosting to a separate bowl or simply turn off the mixer. Then, take a sturdy rubber spatula and vigorously stir and press the buttercream by hand against the sides of the bowl for several minutes. This technique helps to push out excess air, resulting in a dense, silky-smooth frosting that’s a dream to spread and looks incredibly professional on your cake.
4. Utilize an Offset Spatula for Effortless Spreading: An offset spatula is an invaluable tool for frosting cakes. Its angled blade allows you to spread frosting smoothly and evenly across the cake’s surface and sides without your knuckles dragging through the frosting. It makes achieving a beautifully finished cake much easier and gives you more control, especially for the top layer of peanut butter frosting and marshmallow fluff.
5. Don’t Overmix Your Batter: While the cake batter itself is quite forgiving, it’s still best practice to mix only until the ingredients are just combined and no streaks of flour remain. Overmixing can overdevelop the gluten in the flour, leading to a tough, dense cake with a less desirable texture. Mix on low speed and use a spatula to finish combining by hand if necessary to be gentle.
6. Calibrate Your Oven Regularly: Ovens can vary wildly in temperature accuracy, which can significantly impact baking results. Consider investing in an inexpensive oven thermometer to ensure your oven is truly at the temperature you set it to. An accurately calibrated oven prevents under or over-baking, which is essential for that perfectly moist chocolate cake.

Frequently Asked Questions About This Delicious Snack Cake

Here are some common questions and helpful answers to ensure your Chocolate Peanut Butter Marshmallow Snack Cake turns out perfectly every time:

Can I use a 9×9 inch pan instead of an 8×8 inch pan?

Absolutely! This recipe works beautifully in either an 8×8 or a 9×9 inch pan. If you opt for the slightly larger 9×9 inch pan, your cake will be marginally thinner, and you might need to adjust the baking time slightly. Begin checking for doneness a few minutes earlier than the recipe suggests (around 30-35 minutes) to avoid overbaking. The visual cues (like the toothpick test) remain the most reliable indicator, so trust your judgment.

Can I double this recipe for a larger gathering?

Yes, this recipe doubles incredibly well and is perfect for feeding a larger crowd! To accommodate a doubled recipe, you can easily bake it in a 9×13 inch pan. Just remember to double all ingredients for both the cake batter and the peanut butter frosting. The baking time for a 9×13 inch pan might increase slightly, typically to around 40-50 minutes, so keep a close eye on it and perform the toothpick test for doneness.

Can I turn this cake into cupcakes?

Indeed, you can! This recipe translates wonderfully into cupcakes. It will yield approximately 18 standard-sized cupcakes. Fill your cupcake liners about two-thirds full in a muffin tin and bake for a shorter duration, typically 16-18 minutes, or until a toothpick inserted into the center comes out clean. For a fun and beautiful frosting technique, pipe half of the peanut butter frosting and half of the marshmallow fluff side-by-side into a piping bag to create a stunning swirl of both toppings on each cupcake.

What if my homemade marshmallow fluff is too sticky to spread?

Homemade marshmallow fluff can indeed be a bit sticky. If you find it difficult to spread smoothly, lightly grease your offset spatula with a tiny bit of neutral oil (like vegetable or canola) or a little non-stick cooking spray. You can also lightly dampen the spatula with water. This creates a subtle barrier that prevents sticking and allows for much smoother, easier spreading of the fluff across your cake.

Can I make the cake or frosting components ahead of time?

Absolutely, this recipe is quite flexible for advance preparation! The chocolate cake layer can be baked up to 1-2 days in advance. Once completely cooled, wrap it tightly in plastic wrap and store it at room temperature. The peanut butter frosting can also be made a day or two ahead. Store it in an airtight container in the refrigerator. Before using, allow it to come to room temperature and then re-whip it with your electric mixer for a minute or two until it’s light and fluffy again. The homemade marshmallow fluff, however, is best made and used the day of assembly for optimal texture and airiness.

Storing and Freezing Your Chocolate Peanut Butter Marshmallow Snack Cake

Proper storage is key to enjoying your delicious cake for as long as possible while maintaining its exquisite taste and texture. Here’s how to keep your Chocolate Peanut Butter Marshmallow Snack Cake fresh:

Storing

To maintain optimal freshness and texture, store your Chocolate Peanut Butter Marshmallow Snack Cake in an airtight container. You can keep it at room temperature for up to 2 days, especially if your home is cool. However, for longer storage, or if your kitchen tends to be warm, it’s best to store the cake in the refrigerator for up to 5 days. We highly recommend covering the cake with a layer of plastic wrap directly over the frosted surface before placing it in an airtight container. This double protection helps prevent it from drying out, absorbing any fridge odors, and keeps the marshmallow fluffy.

Freezing for Future Enjoyment

This snack cake freezes wonderfully, making it perfect for meal prepping desserts, saving leftovers, or preparing for a future occasion. You can freeze it either whole or cut into individual slices. If freezing whole, ensure the cake is completely chilled and the frosting is firm to the touch. Then, wrap the entire cake tightly in several layers of plastic wrap, followed by a layer of heavy-duty aluminum foil, to prevent freezer burn and protect its delicate layers. For individual slices, wrap each piece separately in plastic wrap and then place them in an airtight freezer-safe container or bag. The cake can be frozen for up to 1-2 months without significant loss of quality.

To Thaw: When you’re ready to enjoy this delightful treat, simply transfer the frozen cake (or individual slices) to the refrigerator overnight to thaw gently. For a quicker thaw of individual slices, you can leave them at room temperature for an hour or two. Once thawed, bring the cake to room temperature before serving for the best possible experience.

How to Serve: Once your cake is beautifully frosted, you can cut it into 9 generous squares, 12 medium-sized portions, or even 16 smaller pieces, depending on how large you want your servings to be. For the absolute best flavor and texture experience, serve the cake at room temperature. This allows the chocolate cake to be its softest, the peanut butter frosting its creamiest, and the marshmallow fluff its lightest. A fun serving suggestion, as my husband enjoys it, is in a bowl with a splash of cold milk – a delightfully nostalgic twist that tastes just like a deconstructed peanut butter cup!

More Cake-Babe Favorites to Bake!

If you loved this recipe and are looking for more delightful treats, explore our other popular snack cakes and irresistible chocolate desserts:

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Recipe

Chocolate Peanut Butter Marshmallow Snack Cake

Molly Murphy

Dark chocolate cake layer, with a creamy and smooth peanut butter frosting, topped with a homemade marshmallow fluff.

5 from 5 votes

Print Recipe
Pin Recipe

Course Dessert

Cuisine American

Servings 8

Ingredients

For the chocolate cake

• 2 eggs room temperature
• ½ cup buttermilk room temperature
• ½ cup hot water
• ¼ cup vegetable oil
• 1 cup all-purpose flour
• ¾ cup granulated sugar
• ½ cup dark cocoa powder
• 1 teaspoon baking soda
• 1 teaspoon baking powder
• ¾ teaspoon salt
• 2 teaspoons pure vanilla extract

For the peanut butter frosting

• 2 ½ cups powdered sugar measured and then sifted
• ½ cup unsalted butter room temperature
• ½ cup creamy peanut butter I use Skippy
• 1 tablespoon pure vanilla extract
• 2-3 tablespoons heavy whipping cream
• Pinch of salt

For the marshmallow fluff

• Note: you can just buy a 7 ounce jar of marshmallow fluff if you don’t want to make your own
• 2 egg whites room temperature
• Pinch of salt
• 3 tablespoons granulated sugar
• ½ cup light corn syrup
• 2 tablespoons water 29.6 g
• 1 teaspoon vanilla extract

Instructions

For cake

• Preheat your oven to 325 degrees F. Spray an 8×8 square inch cake pan with cooking spray, line with parchment paper, and spray again. Set aside.
• In a stand sized mixer fitted with the paddle attachment, combine the flour, sugar, cocoa powder, baking soda, baking powder, and salt. Mix on low until evenly combined.
• In a small bowl, whisk the eggs, buttermilk, hot water, vanilla extract, and vegetable oil until evenly combined.
• With the mixer on the lowest speed, pour the liquid ingredients into the dry ingredients and mix just until combined. There should be no flour streaks. With a rubber spatula, scrape the bottom of the bowl to make sure the batter is evenly combined.
• Add the the batter to the prepped pan, and carefully smooth the batter with a small offset spatula and bake until a toothpick comes out clean, or with only a few crumbs on it, about 35-40 minutes. Depending on your oven.
• After they are out of the oven, I let mine cool for 15 minutes. Then I transfer the cake onto a wire rack to finish cooling in the fridge or freezer to help speed up the process. (20 minutes in the freezer, 30 minutes in the fridge)
• While the cake is cooling, make the frosting.

For the peanut butter buttercream

• In the bowl of electric mixer fitted with the paddle attachment, combine the butter and peanut butter. Beat on medium-high speed until smooth, about 2 minutes.
• With the mixer on the lowest speed, add the powdered sugar, vanilla, salt, and cream to the bowl. Once mixed, beat on high for 3 minutes, scrape down the bowl and beat for 1 more minute. It should look light and fluffy.
• Use a wooden spoon to mix frosting one last time to get rid of air bubbles.

For the marshmallow fluff

• In the bowl of a standing mixer, use a whisk to combine the eggs and salt until frothy, once frothy, keep the mixer on the lowest speed to keep the stabilized.
• While the egg whites are whipping, in a small sauce pan, combine the sugar, corn syrup, water and vanilla over medium heat. You want the sugar to dissolved, so roughly 3-5 minutes.
• Once the sugar has melted, turn the the mixer on medium-high speed, and slowly start to pour the hot sugar mixture on the mixing bowl’s inside rim, letting it run down the side of the bowl. Make sure to pour VERY slowly. If you do this correctly, you will temper your eggs, and not scramble them. This will take about 2 minutes.
• Once all of the sugar has be added, turn the mixer up to high speed, and beat for about 5 minutes or until very stiff and shiny. (This does not hold well, so make sure to to use day of.

Assembly

• Once the cake has cooled (or chilled) and is no longer warm, using the peanut butter frosting, frost the top of the cake. To achieve this, I use a small offset spatula and a large cookie scoop to scoop 9 balls across the top. This help the frosting spread evenly.
• Next add the marshmallow fluff and evenly spread, you might not use all of the marshmallow fluff, you can store the left over in a plastic bag and freeze it for up to 3 months,
• Cut into 9-12 slices and serve!