Chocolate S’mores Cake with Homemade Marshmallow Fluff

Chocolate S'mores CakeI wanted to wait until January was over to share this Chocolate S’mores Cake with you because I know a lot of you were focused on getting back into your healthy habits for the new year, and I didn’t want to be a source of cruel temptation.

Chocolate S'mores CakeBut now that we’re into the thick of February, which might as well be national chocolate month if it isn’t already (is it? Nope. I just googled. National chocolate day is Oct. 28 though so mark your calendars), and we’re only a week away from Valentine’s Day, I figure we’re in safe territory.

Chocolate S'mores CakeFirst of all, I’m obsessed with all things S’mores. This Chocolate S’mores Cake has been swimming around in my brain for months now, and although I am in no way claiming to be the first person ever to bake a s’mores inspired cake, I had yet to come across one that had been assembled exactly the way I was picturing it in my head. Even when I explained it to a friend she had a totally different idea- who knew s’mores cakes could be so subjective?

Chocolate S'mores CakeChocolate S'mores CakeSo let me break down my rustic version of a Chocolate S’mores Cake for you: I wanted a smaller (6 inch), tall (as in 4 layers) chocolate cake. In between each layer is a homemade marshmallow fluff with a graham cracker crumb swirl, and instead of frosting- because you want to be able to see all that gorgeous white fluff- chocolate ganache dripping down the sides.

Chocolate S'mores CakeThen to top it all off more marshmallow fluff that’s been toasted OF COURSE, and a little extra sprinkle of graham crumbs. Side note- making marshmallow fluff from scratch is so not hard and very worth it. I made mine with honey rather than corn syrup. The honey flavor comes through and complements the graham cracker, and also lends a natural, homemade flavor that ties in with that whole rustic vibe I was going for with this S’mores Chocolate Cake.

Chocolate S'mores CakeMaybe it’s because I don’t really have it in me to meticulously decorate a cake, but the naked style just appeals to me more. Call me lazy…I especially love it with this particular cake, because look how the clouds of fluff are puffing out in between each layer. Just YES. It reminds me of a giant stack of Oreos, and it gives the cake a sort of towering and whimsical feel.

Chocolate S'mores CakeBut 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.

Chocolate S'mores Cake

If you make this Chocolate S’mores Cake, please share a photo on Instagram and tag #LePetitEats. I’d love to see it!

Chocolate S'mores Cake with Homemade marshmallow Fluff

Course Dessert
Prep Time 1 hour
Cook Time 15 minutes
Total Time 1 hour 15 minutes
Servings 4 -6
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 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 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.


Chocolate S'mores Cake

Chocolate S'mores Cake

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