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.a slice of Chocolate S'mores Cake with homemade marshmallow fluff filling and graham cracker crumbsI 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.

overhead shot of Chocolate s'mores cake decorated with Graham Cracker crumbs and chocolate ganache But now that we’re into the thick of February, which might as well be national chocolate month if it isn’t already and we’re only a week away from Valentine’s Day, I figure we’re in safe territory.

S’mores Cake – all your favorite campfire s’mores ingredients in one impressive layer cake

three freshly baked chocolate cake layers ready to be stacked with marshmallow fluff to make s'mores cake recipeFirst 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. 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?

So let me break down my Chocolate S’mores Cake for you: I wanted a smaller (6 inch), tall (as in 4 layers) chocolate cake.

In between each layer of moist chocolate cake is a homemade marshmallow fluff fillling with a graham cracker crumb swirl.

Instead of frosting- because you want to be able to see all that gorgeous white fluff- chocolate ganache dripping down the sides. Then to top it all off more marshmallow fluff that’s been toasted OF COURSE, and a little extra sprinkle of graham crumbs. 

How to make Chocolate S’mores Cake:

Preheat the oven to 350°. Lightly spray four 6-inch round cake pans with cooking spray. In a medium bowl, whisk together the dry ingredients for the chocolate cake. 
 
Form a hollow  in the middle of the dry ingredients, and pour in oil, vanilla, vinegar and cold water. Stir to combine very well and pour the cake batter into the prepared pan.
 
Bake your chocolate cake for about 15 minutes, or until a toothpick inserted in the center comes out clean. Remove from oven and cool completely before assembling.

a picture collage demonstrating how to make homemade marshmallow fluff

How to make marshmallow fluff at home: 

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 Cake recipe.

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.

Place egg whites and cream of tartar in a very clean metal bowl. When the sugar syrup reaches about 225°, begin whipping the egg whites until soft peaks form, about 3-4 minutes. 
 

When the sugar syrup reaches 240°F, remove from heat. Turn your mixer to medium speed and very slowly and carefully pour the hot sugar syrup into the egg whites in a thin, steady stream.

Set  the mixer to medium-high speed and continue whipping your homemade marshmallow fluff until thick, fluffy and glossy, about 6-7 minutes.
 

Add in the vanilla essence and whip gently until incorporated. Spoon about 1/3 of the marshmallow fluff 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.

a chocolate sponge cake being covered with homemade marshmallow fluff to make S'mores Cake

How to make the perfect chocolate ganache for cake decoration: 

To make the ganache, place dar 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.

Do not heat too much and make sure no water gets into the mixture. Remove your ganache from the heat and let cool slightly.

a tall Chocolate S'mores Layer Cake with Chocolate Ganache Topping on a wooden cake stand

How to assemble the S’mores Cake like a pro: 

Place one chocolate cake layer on a cake stand or a big flat serving plate. Spread a layer of the homemade marshmallow fluff from the mixing bowl over the cake, making it level.

Top with graham cracker crumbs. Repeat the same steps with the remaining cake layers, marshmallow fluff, and graham cracker crumbs. Reserve a small amount of graham cracker crumbs for decorating the top of the s’mores  cake.

Drizzle the chocolate ganache over the top of the cake, letting it run down the sides a bit. Place your chocolate marshmallow layer cake in the refrigerator for 10-15 minutes.
 

When the ganache has set, remove the s’mores cake from the refrigerator and pipe rounds of marshmallow fluff around the top of the cake.

Lightly toast  the marshmallow fluff swirls using a culinary torch. Sprinkle the  top of  chocolate marsmallow cake with additional graham cracker crumbs. Refrigerate until just before serving.

overhead shot of a layered Chocolate S'mores Cake topped with chocolate ganache and toasted marshmallow fluff swirlsLook how the clouds of fluff are puffing out in between each layer. Just YES. This chocolate marshmallow dessert reminds me of a giant stack of Oreos, and it gives the S’mores Cake a sort of towering and whimsical feel.

a half eaten piece of Chocolate S'mores Cake with homemade marshmallow fluff filling on a pale blue plate

Can this S’mores Cake be refrigerated? 

Yes, you can refrigerate the cake for a bit. Note that the marshmallow fluff under the toasted ganache will start to soften fairly quickly. With time, it will turn a bit soft due to both the  refrigeration and the contact with the chocolate cake and ganache. It won’t impact the flavor of your lovely chocolate layer cake though.

That said, I wouldn’t store it for longer than a couple of days because the fridge tends to dry cakes out rather quickly.
overhead shot of two slices of Chocolate S'mores Cake on pale blue plates

Tips for making this S’mores Cake recipe: 

  • Take care to ensure that each layer of the cake is smooth and level.
  • 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. 

More decadent chocolate desserts for special occasions: 

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

Chocolate S'mores Cake
5 from 5 votes
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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

Ingredients

FOR THE CAKE:

  • 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

FOR THE GRAHAM CRACKER SWIRL MARSHMALLOW FLUFF:

  • 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

FOR THE CHOCOLATE GANACHE:

  • ¾ cup dark chocolate chips
  • 2 tablespoons butter

Instructions

  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. 

PRODUCTS I RECOMMEND FOR THIS RECIPE:



 

a half-eaten piece of Chocolate S'mores Cake with a fork

S’mores Cake – an indulgent layer cake that bring us back to our favorite campfire treat. A moist chocolate cake layered with homemade marshmallow fluff, graham cracker crumbs and a dark chocolate ganache for a stunning decoration. Perfect for special occasions like a birthday, Christmas, a Wedding or Valentine’s Day. #chocolatecake #cakerecipes #smores #holidaybaking #layercake

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