This cake. Let me tell you, it’s a wild ride. Rich and fudgy chocolate cake filled with toasted marshmallow frosting, graham cracker crumble, and peanut butter cream cheese filling all frosted with a smooth and velvety chocolate faux meringue buttercream. Top it with ganache drips, more graham cracker crumble and toasted marshmallows, and this peanut butter s’mores cake is out of this world delicious and very much a crowd pleaser.
Peanut Butter S’mores Cake Contents
If you’ve been around this little corner of the web, then you know this cake is going to have multiple fillings and decorations. Why so complicated, you ask? Cakes can be so boring. Adding different textural AND flavor elements really amps up a cake’s WOW factor. Which I feel like is an important thing, considering layer cakes are made to make a statement, ya know?
Cake contents:
- Rich chocolate cake
- Toasted marshmallow frosting
- Graham cracker crumble
- Peanut butter cream cheese filling
- Chocolate faux meringue buttercream
Chocolate Cake
This is my go-to oil based chocolate cake. It’s rich and stable; bakes up mostly flat and is incredibly easy to work with. It comes together quickly and stays moist for days.
A note about some of the cake ingredients:
- Oil – This is an oil based cake, so that means no butter. A neutral oil is best used here – canola, or vegetable.
- Dutch cocoa powder – Only Dutch processed can be used here. It gives the cake a rich, decadent chocolate flavor.
- Coffee – The coffee in this recipe is meant to enhance the flavor of the chocolate, not for the cake to taste like coffee. Most people won’t even know it’s in there, but if you’re very against coffee, hot water will work in it’s place.
Graham Cracker Crumble
Only 3 ingredients are needed for the graham cracker crumble.
- crushed graham crackers
- melted butter
- pinch of salt
Why is it a crumble? Because the graham crackers, butter and salt are mixed together and baked, resulting in a crumble. After the crumble cools, it can be broken into smaller pieces for adding to the cake.
Peanut Butter Filling
Oh my, this peanut butter filling. It’s so good, it’s hard to not eat it all before it even makes it into the cake. Here’s how to make it:
- Peanut butter and butter are beaten until fluffy and whipped, about 3 minutes.
- Cream cheese is beaten in until smooth.
- Add the milk and the powdered sugar, beating on low until just combined.
- Beat on medium speed for one minute to make sure everything is properly mixed.
Toasted Marshmallow Frosting
Ingredients:
- Toasted marshmallows
- Marshmallow fluff
- Butter
- Powdered sugar
- Salt
- Vanilla
Beat together the butter, powdered sugar, salt and vanilla on medium speed for 3-5 minutes, until light and fluffy. Beat in the marshmallow fluff and the toasted marshmallows. Beat until *just* combined.
Chocolate Buttercream
Faux meringue buttercream is the answer to those who love meringue style buttercream, but don’t want to deal with the hassle of heating egg whites. Faux meringue buttercream is also a tad sweeter than traditional meringue buttercream which is very appealing to people who tend to favor traditional American style buttercream. And, this recipe couldn’t be easier.
Beat the pasteurized egg whites and powdered sugar together to get super light and fluffy, like a meringue. Add in the butter and beat until the buttercream is silky and smooth. Add in the salt, vanilla, and cooled melted chocolate and beat until well combined and fluffy.
So, so good. One of my absolute favorite buttercream recipes.
Cake Assembly
I love to make towering 4 layer cakes, so you can bake this cake into 2 – 2″ cake pans, and torte (or slice in half), resulting in 4 layers. Or, you can bake the cake in 3 separate pans, and no torting is necessary. For a 3 layer cake, divide the fillings into two layers, between the 3 layers of cake.
Order of cake assembly for a 4 layer cake:
- Cake layer
- (1/3) Toasted marshmallow frost
- (1/4) Graham cracker crumble
- Dam of chocolate buttercream
- (1/3) Peanut butter filling
Repeat for an additional 2 layers of filling and 3 more layers of cake. Frost the cake with the chocolate buttercream, and if you like, add some ganache drips. Cut some large marshmallows in half and place them on the cake. Toast them with a kitchen torch, taking care to not melt the buttercream. Sprinkle more graham cracker crumble on top.
Serving and Storing Cake
The cake can be stored in the refrigerator for up to 3 days. This cake is best served at room temperature cut into slices or wedges. Once the cake has been cut into, cover the cake with plastic wrap when storing in the refrigerator.
This cake can also be frozen. For best results, I recommend waiting to frost it until ready to use. Thaw completely in the refrigerator before frosting.
If you make my peanut butter s’mores cake, let me know! Drop a comment below or tag me on Instagram.
Enjoy!
Ash xx
For more layer cake recipes, check out these posts:
Chocolate Hazelnut Praline Cake
Almond Peach Biscoff Cake with Ducley Faux Meringue Buttercream
Smoked Old Fashioned Cocktail Layer Cake
Strawberry Rose Buttermilk Cake
Peanut Butter S’Mores Cake
Ingredients
Chocolate Cake
- 2½ cups (320g) all purpose flour
- 2¼ cups (428g) granulated sugar
- 1 cup (120g) Dutch process cocoa powder
- 2 teaspoons baking powder
- 2 teaspoons baking soda
- ¾ teaspoon fine sea salt
- 1¾ cups (397g) buttermilk, room temperature
- ¾ cups (170g) hot coffee
- ¾ cup (149g) canola oil
- 3 large eggs, room temperature
- 2 teaspoons pure vanilla extract
Graham Cracker Crumble
- 1 cup (142g) graham crackers, crushed
- 2 tablespoons unsalted butter
- ⅛ teaspoon fine sea salt
Toasted Marshmallow Frosting
- 20 large marshmallows
- ¾ cup (170g) unsalted butter, room temperature
- 1 ¼ cups (142g) powdered sugar
- 1 teaspoon pure vanilla extract
- 1 jar (7oz/198g) marshmallow fluff
Peanut Butter Filling
- ½ cup (135g) peanut butter
- 4 tablespoons unsalted butter, room temperature
- ½ cup (114g) cream cheese, room temperature
- 2 cups (227g) powdered sugar
- 2 teaspoons milk
Chocolate Faux Meringue Buttercream
- ¾ cup (170g) pasteurized carton egg whites
- 4 cups (454g) powdered sugar
- 3 cups (678g) unsalted butter, room temperature
- ½ teaspoon fine sea salt
- 2 teaspoons pure vanilla extract
- 1 cup (170g) semi or bittersweet chocolate, melted and cooled
- Ganache, toasted marshmallows and graham cracker crumble, for decorating (optional)
Instructions
Chocolate Cake:
- Preheat the oven to 350F. Prepare the cake pans. You can use 3-8" pans for a 3 layer cake, or 2 -8" pans, then torte in half, for a 4 layer cake. Brush the bottoms and sides of your cake pans with melted butter. Line the bottoms and sides with parchment paper
- In the bowl of a stand mixer fitted with the whisk attachment, combine the flour, sugar, cocoa powder, baking powder, baking soda and salt.
- In a bowl or a large measuring cup, whisk together the buttermilk, coffee, oil, eggs and vanilla.
- With the mixer speed on low, whisk the dry ingredients for 1 minute to fully combine.
- Add the buttermilk mixture in 3 parts, scraping the bowl with a spatula after each addition.
- Beat on low-medium speed for 1 minute. Give the bowl a final scrape down with the spatula.
- Divide the cake batter between the pans.
- Bake for 25-30 minutes, for 3 cake pans.Bake 40-50 minutes, if using 2 cake pans.Bake until a toothpick inserted in the center comes out clean.
- Let the cakes cool on cooling racks for 15 minutes. Run a palette or butter knife around the cakes in their pans before turning them out to cool completely on cooling racks.
- Wrap in plastic wrap and chill in the refrigerator until ready to use.
Graham Cracker Crumble
- Line a small cookie sheet with parchment paper.
- In a medium bowl, melt the butter in the microwave, about 30-45 seconds.
- Add the crushed graham crackers and salt to the bowl and stir to coat.
- Pour the crumble onto the parchment paper in an even layer.
- Bake for 8 minutes. Cool completely and break into smaller pieces, if necessary.
Toasted Marshmallow Frosting
- Preheat the oven to broil. Line a sheet pan with parchment paper.
- Place the marshmallows on the sheet pan in an even layer.
- Broil the marshmallows, keeping a constant eye on them, for 2-3 minutes, or until golden brown.
- Flip the marshmallows over and place back in the oven for 2 additional minutes, keeping an eye on them as they cook.
- Let the marshmallows cool completely.
- In the bowl of a stand mixer, fitted with the paddle attachment, beat the butter for 5 minutes, until light and fluffy.
- Beat in the powdered sugar, and vanilla. Beat for 2 more minutes.
- Add in the marshmallow fluff and toasted marshmallows, beating just until combined.
Peanut Butter Filling
- In the bowl of stand mixer, fitted with the paddle attachment, on medium speed, beat the butter and peanut butter for 2- 3 minutes, until lightened, smooth and fluffy.
- Turn the speed to medium low and beat in the cream cheese, until smooth, about 2 minutes.
- Add in the powdered sugar and vanilla and beat until combined, about 2 minutes.
- Give the sides and bottom of the mixing bowl a scrape with a spatula. Beat for an additional 30 seconds.
Chocolate Faux Meringue Buttercream
- In the bowl of a stand mixer fitted with the paddle attachment, place the pasturized egg whites and powdered sugar. Mix on low speed until combined.
- Turn the mixer up to medium-high speed and mix for 7-8 minutes.
- Turn the speed down to medium-low and add the butter, a few pieces at a time.
- Add the salt and vanilla. Scrape down the bottom and sides of the bowl with a spatula.
- Turn up the speed to medium and beat the buttercream for 10 minutes. It might look curdled at first, but keep mixing, it will come together to become creamy and smooth.
- Add the room temperature melted chocolate and mix on low until completely combined.
Cake Assembly
- Work with chilled cake layers. Using a long serrated knife torte the layers, cutting them evenly in half. You will have four cake layers total. The tops of the cakes will be the center two layers of your cake. If you made your cake in 3 pans, skip this step
- Put one of the cake layers, cut side up onto an 8" cake board or directly onto a cake stand.
- Spread 1/3 of the toasted marshmallow frosting evenly on the layer.
- Sprinkle 1/4 of the graham cracker mixture on top of the marshmallow frosting.
- Fit a piping bag with a large round tip ( I use an Ateco 808), and fill with chocolate buttercream.
- Pipe a dam around the perimeter of the cake layer with the chocolate buttercream.
- Spread 1/3 of the peanut butter filling evenly on the layer within the dam, on top of the graham cracker crumble.
- **If making a 3 layer cake, divide the marshmallow frosting and peanut butter filling in half between the two layers of filling. Use 1/3 of the graham cracker crumble between the two layers of filling.**
- Add the second cake layer and repeat with another 2/3 of the marshmallow frosting, 1/4 of the graham cracker crumbles, chocolate buttercream dam and 1/3 of the peanut butter filling.
- Add the third cake layer and repeat with another 2/3 of the marshmallow frosting, 1/4 of the graham cracker crumbles, chocolate buttercream dam and 1/3 of the peanut butter filling.
- Place final cake layer on top and frost with the remaining buttercream. Chill for 30 minutes. Decorate.
- *Optional* Top with ganache drip, toasted marshmallows and additional graham cracker crumbles.
