S'mores peanut butter cake- 3 layer moist chocolate cake, peanut butter marshmallow creme filling, chocolate ganache filling, and peanut butter buttercream. Topped with a chocolate ganache drip with 4 toasted marshmallows.
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The Best S'mores Peanut Butter Cake
I actually made this cake for my birthday and it was such a hit. It has 3 layers of chocolate cake that is super moist and tender. It has one layer of peanut butter marshmallow filling and one layer of chocolate ganache. Topped with a SUPER amazing peanut butter buttercream and a chocolate ganache drip. Plus, some toasted marshmallows. YES PLEASE.
I used to not know much about decorating cakes and wish someone could have shown me all of the ways to make a gorgeous looking cake. Today I am going to be your pal and give you all the tips and tricks.
Moist Chocolate Cake
Making an amazing chocolate cake is very important. i\It is the base of the whole cake after all! This chocolate cake is very moist and tender because I wanted to make sure it doesn't dry out with all the peanut butter.
What makes this cake so moist is adding both buttermilk and hot water.
Buttermilk has high amount of acidity, like sour cream or yogurt, which helps tenderize the gluten in the flour. It breaks down the tough strands of gluten and results in a very tender and moist cake. I love adding buttermilk to my cakes because there is nothing better than a moist cake.
Adding hot water to the chocolate cake mostly has to do with the flavor. The heat from the water helps to pull the cocoa powder to the surface. It helps to bloom the yummy chocolate flavor. Hot water also helps to steam the cake.
To get even cake:
- Sift all of the dry ingredients together.
- For high altitude baking add 2 tablespoon extra of sifted cake flour.
- Slam the cake pans down on the counter to get rid of any air bubbles.
- Don't over mix the batter. Over mixing gives the cake more air bubbles which can cause it to collapse or sink in
- If the cake bakes unevenly or if there is a dome on top, use a cake leveler to make the cakes flat. Do this once the cake has been chilled. I use this cake leveler.
Place the cake batter on top of the pre-baked graham cracker crust and bake for 18 minutes. The cake is finished when there are a few moist crumbs on a toothpick inserted into the cake.
The peanut butter marshmallow creme is one of the best things about this whole cake. It is delicious and full of flavor. It is also easy to make!
Combine the peanut butter, marshmallow creme, cinnamon and milk until it is smooth. Then, slowly add in the powdered sugar and mix it together until creamy. I can't even describe why this filling is so good, it just is! You will only use half of this filling so you can use it on whatever else you want! I used this filling for these peanut butter and chocolate cupcakes.
The second filling is chocolate ganache. The chocolate ganache is full of rich chocolate flavor and is simple to make. Plus, it is only made with 2 ingredients, hot heavy cream and chocolate chips.
I wanted to combine both the marshmallow and chocolate flavors to make it scream yummy s'mores.
Peanut Butter Buttercream
Making this buttercream in a stand mixer is a must! The stand mixer will supply the power to whip this buttercream until it is light and fluffy.
The butter should be slightly cold. Leave cold butter on the counter for 30 minutes. You should be able to leave a slight imprint of your finger. Making buttercream with room temperature butter doesn't work as well. It is too soft to be able to pipe and decorate with.
Beat the slightly cold butter for 1 minute on medium high. Then, add in the peanut butter and beat again for another minute. Next, slowly add sifted powdered sugar on low. The powdered sugar should always be sifted because you don't want any clumps in the buttercream.
After the powdered sugar is combined, add in the heavy cream and beat again for 4 minutes. The buttercream will become light in color and look very fluffy. Make sure to scrape the bowl and then beat again for another minute.
After it has been beaten, use a wooden to spoon and mix by hand to get rid of air bubbles. This peanut butter buttercream is so delicious. It tastes even better cold. Be sure to only decorate the cake with room temperature buttercream. Then, after the cake is all finished make sure to chill it because it will be a lot easier to cut into when it's cold!
Assembling the S'mores Peanut Butter Cake
What really helps when transporting this s'mores peanut butter cake between chilling is to use cardboard cake circles. Tape an 8 inch cake circle to a 10 inch cake circle. The 10 inch is to make it easy to move the cake. When the cake is all finished, you will take the 10 inch cake circle off.
Place a small amount of buttercream on 8 inch cake circle. The buttercream will act as a glue to keep the cake in place. For each layer of cake, make sure to put crust bottom side down. Normally for regular cake, the top layer of cake is placed with the bottom side up to get a smoother top. However, this cake has the graham cracker crust, so each layer is bottom side down.
Pipe a thick ring of butter cream around the edge of the cake. This ring will act as a barrier so none of the good filling will escape. Pour half the marshmallow creme and smooth it flat.
Next, place the next layer of cake and repeat with the ring of buttercream. Pour chocolate ganache on top and smooth it flat. Place the final layer of cake on top.
Take the peanut butter buttercream and ice the cake with a very light layer of frosting. This is the crumb coat. The frosting should be very thin on the cake that you should be able to see little bits of the cake. Use an icing scraper to smooth the frosting. I use this one. Place the cake in the freezer for 15 minutes.
Frosting The Cake
Take the cake out of the freezer and place an 8.5 inch acrylic disc on top. I use this one. The acrylic disc helps to get very smooth and sharp edges and has been a cake life saver! Frost the rest of the cake with the buttercream.
The best way to get smooth edges is to use the icing scraper and a cake turn table. Rotating the cake in a smooth motion really makes the difference. You will have to smooth the cake probably several times to get it smooth. Be sure to not go over 15 minutes because the buttercream gets too overworked.
Then, place the cake in the freezer for 10 minutes. The acrylic disc will be still on top of the cake. After the cake is in the freezer, take a knife and slowly pry the disc off. Next, frost the top of the cake until smooth.
Decorating The S'mores Peanut Butter Cake
Next, make the chocolate ganache drip and pour some into a squeeze bottle. Start by the edge of the cake. Push the chocolate to the edge of the cake and allow it to drip down. Then, go around the whole cake until it has drips around the sides. Pour more ganache on the top and smooth it flat.
To get the circle effect: I used an icing spatula and a turn table. The ganache will be too slick to decorate. Place the cake in the freezer for 20 minutes, so the chocolate can set.
Next, use graham cracker crumbs to decorate the bottom of the cake and the top of the cake. I poured the crumbs in a circle on top of the ganache.
Almost done! Next, it is time to toast the marshmallows. I use this torch. It is actually pretty awesome! If you don't have a torch, you can broil the marshmallows. Broil the marshmallows on high on a cookie sheet. Be sure to rotate them every minute. They will only need 2-3 minutes, but make sure to watch them because they can burn easily! Then, place them on top of the cake. You are now done with this yummy cake!
Other Recipes To Try
Make sure to tag me on Instagram @stephaniesweettreats and leave me review below if you made this cake. I hope you loved it! To get more ideas follow me on Pinterest.
S'mores Peanut Butter Cake
- 3 cups Graham cracker crumbs
- 4 ½ tablespoon Packed light of dark brown sugar
- 6 tablespoon Melted Butter
- 2 cups Cake flour
- 1 ¾ cups White granulated sugar
- ¾ cup Dark 100% unsweetened cocoa powder
- 2 teaspoon Baking soda
- ¾ teaspoon Baking powder
- 1 teaspoon Salt
- 1 ⅛ cup Buttermilk room temperature
- ½ cup Oil canola or vegetable
- 3 Large eggs room temperature
- 1 cup Steaming water
- 1 teaspoon Pure vanilla extract
Peanut Butter Marshmallow Creme
- ¾ cup Creamy peanut butter
- ¾ cup Marshmallow creme
- ¾ teaspoon Ground cinnamon
- 3 tablespoon Milk
- 3 tablespoon Powdered Sugar
Chocolate Ganache Filling
- ⅛ cup Heavy cream
- ¼ cup Semi-sweet chocolate chips
Peanut Butter Buttercream
- 1 ½ cup Slightly cold butter
- 1 cup Creamy peanut butter
- 1 tablespoon Pure vanilla extract
- 6 cups Sifted powdered sugar
- ¼ cup Heavy whipping cream
Chocolate ganache drip
- 1 cup Semi-sweet chocolate chip
- ¾ cup Heavy whipping cream
- ¼ cup Graham cracker crumbs
- 4 Jumbo marshmallow
- Preheat the oven to 350F. Spray 3 8X2 round cake pans with a non stick spray. Place an 8 inch parchment circle on the bottom of each cake pan. Spray again with a non stick spray.
- Using a food processor, pulse the graham crackers until a fine crumb forms. In a small bowl, combine graham cracker crumbs, melted butter, and brown sugar. Use a food scale to separate the graham cracker crust evenly through the 3 cake pans. Use your hands to compact the crust. Bake all 3 crusts for 7 minutes.
- Sift together the cake flour, sugar, baking soda, baking powder, cocoa powder, and salt in a large bowl and set aside. Using a mixer, combine buttermilk, oil, vanilla, and eggs. Slowly add in the steaming water. Slowly add in the dry ingredients.
- Use a food scale again to evenly spread out the batter between the 3 cake pans on top of graham cracker crusts. Bake cake for 17-22 minutes. Cake is finished when a toothpick inserted comes out with moist crumbs. Let cake sit in cake pans for 10 minutes and then transfer cake to a cooling rack. Allow to cool completely and then wrap in saran wrap and place in freezer.
Peanut Butter Marshmallow Creme Filling
- Using a mixer, combine peanut butter, marshmallow creme, cinnamon and milk together. Slowly add in powdered sugar. Set aside.
Chocolate Ganache Filling
- Heat heavy cream in a sauce pan until it starts to steam but not yet boil. Pour hot heavy cream over chocolate chips and let sit for 1 minute and 30 seconds. Then, continuously stir until glossy and smooth and set aside.
Peanut Butter Buttercream
- Let cold butter sit out for 30 minutes, then using a stand mixer beat on medium high for 1 minute. Add in peanut butter and vanilla and beat for another minute. Slowly add in sifted powdered sugar until combined on low. Add in heavy cream. Switch to a whisk attachment and beat on medium high for 4 minutes. Scrape the bowl and beat for another minute. Using a wooden spoon, beat by hand for a few minutes to get rid of any air bubbles. Set aside.
Chocolate Ganache Drip
- Place chocolate chips in a bowl and set aside. Heat ¾ cup of heavy cream for 1 minute in microwave safe bowl. Pour cream over chocolate chips and let sit for 1 minute and 30 seconds and the stir until glossy and smooth. Place ¼ of the ganache in squeeze bottle.
- 1 hour before assembly, place cakes from freezer on counter to get to room temp.
- Using an 8 inch cake circle, place a small amount of frosting and place the first layer of cake crust side down. Pipe a thick ring of buttercream around the edge of the cake. Pour half of peanut butter marshmallow creme and spread it smooth.
- Place the second layer of cake, crust side down. Pipe another ring of buttercream around the edge of the cake. Pour half of chocolate ganache on cake and spread it smooth.
- Place the third and final layer of cake, crust side down. Lightly spread frosting over cake and scrape 'til smooth for the crumb coat layer. Some of the cake should be showing. Freeze for 15 minutes
- Place 8.5 inch acrylic disc on the top of the cake. Spread on frosting and use an icing scraper and smooth the cake. Once smooth, freeze cake with acrylic disc still on for 10 minutes.
- Use a knife to cut off acrylic disc. Frost the top of the cake until smooth. Using ganache in squeeze bottle, drip the chocolate down the sides of the cake. Pour ganache on top of cake and smooth it to the edges. Freeze cake for 20 minutes to set the ganache.
- Using a food processor, crumble graham crackers. Place crumbs on bottom of cake and on top around the edges in a circle. Toast the marshmallows with a torch or the broil setting on high in the oven. If broiling, place on cookie sheet and rotate every minute. Should only take 2-3 minutes. Keep watch because it could burn easy. Place marshmallows on top of ganache.
Yemi King says
my partner will love me more if I make this for him.... I am thanking you in advance 😉
Stephanie Rutherford says
You are welcome! I hope you enjoy!
Wow, this looks delicious! S’mores recipes are some of my favorites, so I’ll definitely pin this to try for myself! 😋
Stephanie Rutherford says
I hope you do try it! It is so yummy!
Heather | The Blessed Mama of 4 says
This cake looks so delicious! I will definitely have to give it a try. Thanks for sharing!
Stephanie Rutherford says
Thank you so much!