Ingredients
Method
- Preheat oven to 350°F (175°C). Grease and line two 8-inch round cake pans with parchment paper.Whisk together flour, cocoa powder, sugar, baking soda, baking powder, and salt in a large bowl.In a separate bowl, whisk eggs, buttermilk, oil, and vanilla. Stir in hot coffee last — batter will be thin.Pour wet ingredients into dry and mix until just smooth. Divide between the two pans.Bake for 28–32 minutes until a toothpick comes out with a few moist crumbs. Cool completely.Mix graham cracker crumbs, sugar, melted butter, and salt. Spread on a baking sheet and bake at 350°F for 8–10 minutes until golden. Cool completely.Beat softened butter on medium-high for 3–4 minutes until pale and fluffy.Add powdered sugar gradually, then marshmallow fluff, vanilla, and salt. Add cream 1 tbsp at a time and beat until light and airy.Place first cake layer on a stand. Spread marshmallow buttercream on top and sprinkle with half the graham cracker crumble.Add the second cake layer and repeat — buttercream then remaining crumble.Apply a thin crumb coat all over the cake. Refrigerate for 20 minutes.Apply the final layer of frosting. Drizzle with chocolate ganache and top with toasted marshmallows and graham cracker pieces.
Notes
Coffee in the batter deepens the chocolate flavor — you cannot taste it in the finished cake.
Use room temperature butter and eggs for the best batter and frosting texture.
Let the graham cracker crumble cool completely before using — it crisps up as it cools.
Always apply a crumb coat and chill 20 minutes before the final frosting layer.
Toast the marshmallows with a kitchen torch right before serving.
Cake layers can be baked 2 days ahead. Crumble keeps 1 week in an airtight container.
Use room temperature butter and eggs for the best batter and frosting texture.
Let the graham cracker crumble cool completely before using — it crisps up as it cools.
Always apply a crumb coat and chill 20 minutes before the final frosting layer.
Toast the marshmallows with a kitchen torch right before serving.
Cake layers can be baked 2 days ahead. Crumble keeps 1 week in an airtight container.