Weigh out the ingredients
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For the cake layers, you'll need flour, graham cracker crumbs, sugar, baking powder, salt, butter, egg, milk, vanilla, and oil.
Weigh out the ingredients
II
For the chocolate frosting and marshmallow fluff, you'll need chocolate, butter, sugar, water, egg white, egg yolks, vanilla, and light corn syrup.
In the bowl of a stand mixer fitted with the paddle attachment, combine the flour, graham cracker crumbs, sugar, baking powder, and salt.
Combine the dry ingredients
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Cut up the butter into small cubes and add to the dry ingredients. Mix on low speed until it resembles wet sand.
Mix in the butter
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Add the oil, milk, egg, and vanilla, and mix until just combined.
Mix in the wet ingredients
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Pour the cake batter into the prepared pans. Bake for 22-25 minutes or until a toothpick inserted comes out clean. Immediately turn the cakes out onto a wire rack to cool completely. Once cool, wrap the cakes in plastic wrap and freeze until ready to decorate. (Frozen cake layers will be much easier to frost!)
Bake
VI
In a small saucepan, heat the water, sugar, and light corn syrup until it reaches 240 degrees F. Beat the egg white to soft peaks. Drizzle the sugar syrup into the egg white while mixing on low speed. Turn the mixer up to high speed until thick and glossy. Lastly, mix in the vanilla extract. Cover the bowl and set aside.
Make the marshmallow fluff
VII
Whisk the egg yolks and sugar on high speed until thick and foamy while you heat the sugar and water. In a small saucepan, heat the remaining sugar and water until it reaches 240 degrees F. Drizzle the sugar syrup into the egg yolks. Add the butter to the mixture. Lastly, add the melted chocolate and vanilla.
Make the chocolate frosting
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Place the first cake layer on a cake stand. Use a 3 tablespoon cookie scoop to add 1 scoop of buttercream and spread into an even layer. Then, add a few scoops of marshmallow fluff and spread into an even layer. Repeat with the next cake layer. Add the last cake layer and continue decorating the cake as desired.
Assemble the cake
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Top the cake with marshmallows, and enjoy!
Enjoy!
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