S’mores Lava Layer Cake Recipe

Serves 12-16 | Prep Time: 45 minutes | Bake Time: 25-30 minutes | Total Time: 2 hours

Ingredients

For the Graham Cracker Cake Layers:

  • 2½ cups all-purpose flour
  • 1 cup graham cracker crumbs (about 8 crackers, finely ground)
  • 2 cups granulated sugar
  • 1 cup unsalted butter, softened
  • 4 large eggs
  • 1 cup buttermilk
  • ½ cup sour cream
  • 2 teaspoons vanilla extract
  • 2 teaspoons baking powder
  • 1 teaspoon salt

For the Chocolate Lava Filling:

  • 8 oz dark chocolate (70% cocoa), chopped
  • ½ cup heavy cream
  • ¼ cup unsalted butter
  • 2 tablespoons corn syrup
  • 1 teaspoon vanilla extract
  • Pinch of salt

For the Marshmallow Frosting:

  • 4 large egg whites
  • 1 cup granulated sugar
  • ¼ teaspoon salt
  • 1 teaspoon vanilla extract
  • ¼ teaspoon cream of tartar

For Assembly and Decoration:

  • 6 full graham crackers, broken into pieces
  • 2 cups mini marshmallows
  • 4 oz milk chocolate, melted
  • Additional graham cracker crumbs for dusting

Instructions

Make the Graham Cracker Cake:

  1. Prepare the pans: Preheat oven to 350°F (175°C). Grease three 9-inch round cake pans and line with parchment paper. Dust with graham cracker crumbs.
  2. Mix dry ingredients: In a medium bowl, whisk together flour, graham cracker crumbs, baking powder, and salt.
  3. Cream butter and sugar: In a large bowl, beat softened butter and sugar until light and fluffy, about 4-5 minutes. Add eggs one at a time, beating well after each addition.
  4. Combine wet ingredients: In a separate bowl, whisk together buttermilk, sour cream, and vanilla extract.
  5. Assemble batter: Alternate adding the flour mixture and buttermilk mixture to the butter mixture, beginning and ending with flour. Mix until just combined.
  6. Bake: Divide batter evenly among prepared pans. Bake for 25-30 minutes, or until a toothpick inserted in center comes out clean. Cool in pans for 10 minutes, then turn out onto wire racks to cool completely.

Make the Chocolate Lava Filling:

  1. Heat cream: In a small saucepan, heat heavy cream until just beginning to simmer.
  2. Melt chocolate: Place chopped chocolate in a heatproof bowl. Pour hot cream over chocolate and let sit for 2 minutes.
  3. Finish ganache: Add butter, corn syrup, vanilla, and salt. Whisk until smooth and glossy. Let cool to room temperature but still pourable, about 30 minutes.

Make the Marshmallow Frosting:

  1. Prepare double boiler: In a large heatproof bowl, whisk together egg whites, sugar, salt, and cream of tartar.
  2. Cook mixture: Place bowl over a pot of simmering water (don’t let bowl touch water). Whisk constantly until mixture reaches 160°F (71°C) and sugar dissolves, about 5-7 minutes.
  3. Whip frosting: Remove from heat and beat with electric mixer on high speed until stiff, glossy peaks form and mixture cools to room temperature, about 7-10 minutes. Beat in vanilla.

Assemble the Cake:

  1. Prepare layers: Using a large knife, carefully slice each cake layer in half horizontally to create 6 thin layers.
  2. First layer: Place one cake layer on serving plate. Spread ⅓ of the chocolate lava filling over the top, leaving a ½-inch border.
  3. Build layers: Add second cake layer and spread with marshmallow frosting. Sprinkle with graham cracker pieces and mini marshmallows. Repeat layering process: cake, lava filling, cake, marshmallow frosting with mix-ins, continuing until all layers are used.
  4. Final frosting: Cover entire cake with remaining marshmallow frosting, creating swirls and peaks for texture.
  5. Torch finish: Using a kitchen torch, carefully toast the marshmallow frosting until golden brown in spots. Work in sections for even browning.

Final Decorations:

  1. Drizzle chocolate: Drizzle melted milk chocolate over the torched frosting.
  2. Add toppings: Press graham cracker pieces around the base and top of cake. Sprinkle with graham cracker crumbs.
  3. Final touch: Top with additional toasted mini marshmallows if desired.

Pro Tips

  • Room temperature ingredients: Ensure all dairy ingredients are at room temperature for best mixing results.
  • Lava effect: For an extra “lava” effect, reserve some warm chocolate ganache to drizzle between layers just before serving.
  • Make ahead: Cake layers can be made 1 day ahead and wrapped tightly. Assemble day of serving for best results.
  • Torching safety: Keep torch moving constantly to avoid burning. If you don’t have a torch, broil the cake for 1-2 minutes, watching carefully.
  • Storage: Store covered at room temperature for up to 2 days. Bring to room temperature before serving if refrigerated.

Serving Suggestion

Serve thick slices with vanilla ice cream and extra graham crackers for the ultimate s’mores experience. The chocolate lava filling will ooze beautifully when cut!