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Chocolate S'mores Cake

Chocolate S'mores Cake with Homemade marshmallow Fluff

S'mores Cake - an indulgent layer cake that bring us back to our childhood. A moist chocolate cake layered with homemade marshmallow fluff, graham cracker crumbs and a dark chocolate ganache. Perfect for special occasions like Valentine's Day.

Course Dessert
Cuisine American
Keyword cake with marshmallow fluff, chocolate layer cake, s'mores cake recipe
Prep Time 1 hour
Cook Time 15 minutes
Total Time 1 hour 15 minutes
Servings 4 -6
Calories 500 kcal
Author Denisse Salinas



  • 1 1/2 cups all-purpose flour
  • 1 cup granulated sugar
  • 3 tablespoons unsweetened cocoa powder
  • 1 teaspoon baking soda
  • 1/2 teaspoon instant espresso powder
  • 1/2 teaspoon salt
  • 6 tablespoons canola oil
  • 1 teaspoon vanilla extract
  • 1 tablespoon white vinegar
  • 1 cup cold water


  • 1/3 cup water
  • 3/4 cup granulated sugar
  • 3/4 cup corn syrup or honey
  • 3 large egg whites room temperature
  • 1/2 tsp cream of tartar
  • 1 tsp vanilla extract
  • 3 graham crackers broken into fine crumbs


  • ¾ cup dark chocolate chips
  • 2 tablespoons butter


  1. Preheat the oven to 350°. Lightly spray four 6-inch round cake pans with cooking spray. In a medium bowl, whisk together the flour, sugar, cocoa, baking soda, espresso powder and salt.
  2. Make a hole in the middle of the dry ingredients, and pour in the oil, vanilla, vinegar and cold water. Stir to combine very well.
  3. Pour the batter into the prepared pan and bake for about 15 minutes, or until a toothpick inserted in the center comes out clean. Remove from oven and cool completely.
  4. Make the marshmallow fluff by placing water, sugar and honey in a medium saucepan. Stir to combine. Insert a candy thermometer into the pot and heat over medium-high.

  5. Place egg whites and cream of tartar in the bowl of a stand mixer. When the sugar syrup reaches about 225°, begin whipping the egg whites until soft peaks form, about 3-4 minutes.
  6. When the sugar syrup reaches 240°F, remove from heat. Turn mixer to medium and very slowly and carefully pour the sugar syrup into the whites in a thin, steady stream.

  7. Set mixer to medium-high and continue whipping until thick, fluffy and glossy, about 6-7 minutes.
  8. Add in vanilla and whip gently until incorporated. Spoon about 1/3 of the mixture into a piping bag fitted with a star tip and set aside. Swirl half of graham cracker crumbs into the mixing bowl with the remaining marshmallow fluff and set aside.

  9. To make the ganache, place chocolate chips and butter in a small saucepan. Heat on medium, stirring constantly once the chips begin to melt until the mixture is smooth and pourable. Remove from heat and let cool slightly.

  10. To assemble the cake, place one cake layer on a cake stand or serving plate. Spread a layer of the marshmallow fluff from the mixing bowl over the cake, making it level. Top with a light layer of graham cracker crumbs. Repeat with remaining cake layers, marshmallow fluff, and graham cracker crumbs, reserving a small amount of crumbs for the top of the cake and taking care to ensure that each layer is smooth and level.

  11. Drizzle the chocolate ganache over the top of the cake, letting it run down the sides a bit. Place cake in the refrigerator for 10-15 minutes.
  12. When the ganache has set, remove from refrigerator and pipe rounds of marshmallow fluff around the top of the cake. Lightly toast marshmallow fluff using a culinary torch. Sprinkle top of cake with additional graham cracker crumbs. Refrigerate until just before serving.

Recipe Notes

  • Don't be concerned about the cake being precarious or unstable. It actually holds together very well and you're able to slice into it quite neatly! Just make sure to chill it a bit before serving so that all the layers have a chance to settle and set.
  • I do NOT recommend store-bought marshmallow fluff. It’s often too thin and runny to hold up in a cake.
  • Make sure you whip your egg whites in a very clean bowl.  Any grease or egg yolk that got in contact with your egg whites will prevent it from getting stiff and fluffy.