Ingredients:

  • 2 cups (250g) all-purpose flour
  • 2 cups (400g) granulated sugar
  • 3/4 cup (75g) unsweetened cocoa powder
  • 2 tsp (10g) baking soda
  • 1 tsp (5g) baking powder
  • 1 tsp (5g) salt
  • 1 cup (240ml) buttermilk
  • 1/2 cup (120ml) vegetable oil
  • 2 large eggs
  • 1 tsp (5ml) vanilla extract
  • 1 cup (240ml) hot coffee
  • 1 1/2 cups (150g) graham cracker crumbs
  • 4 tbsp (56g) unsalted butter, melted
  • 2 tbsp (25g) brown sugar
  • 1/4 tsp (1.5g) salt
  • 1 cup (225g) unsalted butter, softened
  • 1 jar (225g) marshmallow fluff
  • 3 cups (360g) powdered sugar
  • 2 tsp (10ml) vanilla extract
  • 2 tbsp (30ml) heavy cream
  • 4 oz (115g) semi-sweet chocolate, chopped
  • 1/2 cup (120ml) heavy cream

Instructions:

  1. Preheat oven to 350°F (175°C). Grease two 8-inch round cake pans with butter and line the bottoms with parchment paper.
  2. Whisk together flour, granulated sugar, cocoa powder, baking soda, baking powder, and salt in a large bowl.
  3. Add buttermilk, vegetable oil, eggs, and vanilla extract; beat on medium speed until the batter is smooth.
  4. Stir in the hot coffee by hand until combined. The batter will be thin.
  5. Divide batter evenly between the two pans and bake for 30-35 minutes, or until a toothpick inserted comes out with a few moist crumbs.
  6. Cool cakes completely on a wire rack.
  7. Prepare the crumble by mixing graham cracker crumbs, melted butter, brown sugar, and salt. Toast in a pan over medium heat until fragrant and crisp.
  8. Create the frosting by beating softened butter until creamy, then mixing in marshmallow fluff, powdered sugar, vanilla, and heavy cream until fluffy.
  9. Make the ganache by heating 1/2 cup heavy cream and pouring it over chopped semi-sweet chocolate; let sit, then stir until glossy.
  10. Assemble the cake by layering frosting and graham cracker crumble between the chocolate sponges.
  11. Frost the exterior and top of the cake. Pour the chocolate ganache over the edges for a drip effect.
  12. Chill the cake in the refrigerator for 2 hours to stabilize the structure.
  13. Use a kitchen torch or oven broiler to lightly char the marshmallow frosting peaks until toasted golden brown.