Introduction

This decadent S’mores Cake combines all the beloved flavors of a classic campfire treat into a rich, moist layer cake. Layers of chocolate cake with a cookie crust are filled with creamy chocolate and marshmallow buttercream, then topped with toasted marshmallow fluff for the perfect finish. It’s an impressive dessert that’s surprisingly easy to make at home.

A three-layer dark chocolate cake with thick light brown frosting between each layer and covering the outside, topped with a glossy dark chocolate drip down the sides. The cake is decorated with dollops of toasted white meringue on top, each slightly browned and swirled. One large slice is cut out, showing the rich, moist texture of the chocolate layers. The cake sits on white parchment paper on a dark ridged cake stand, all placed on a white marbled surface. A white cloth and a small vase with white flowers are in the background. Photo taken with an iphone --ar 4:5 --v 7

Ingredients

250 grams (8.8 oz) digestive biscuits or graham crackers (add 1 tbsp sugar if using graham crackers)
90 grams (3.17 oz) unsalted butter, melted
2 eggs, room temperature
300 grams (1½ cup, 10.5 oz) granulated sugar
240 grams (1 cup) buttermilk
120 ml (1/2 cup) oil
120 grams (1 cup) cocoa powder
2 teaspoons vanilla extract
240 ml (1 cup) hot strong brewed coffee (or water)
300 grams (2⅓ cup +1 Tablespoon, 10.5 oz) all-purpose flour
2 teaspoons baking soda
1 teaspoon baking powder
½ teaspoon salt
Chocolate Filling:
80 grams (2.8 oz) heavy cream
120 grams (4.2 oz) quality dark chocolate, finely chopped
30 grams (2 tablespoons, 1 oz) unsalted butter
Marshmallow Buttercream:
200 grams (7.05 oz) Marshmallow Creme/Fluff (store bought or homemade)
200 grams (7.05 oz) unsalted butter, room temperature
100 grams (3.5 oz) powdered sugar
1 teaspoon vanilla extract
Pinch of salt
Chocolate Ganache:
100 grams (3.5 oz) dark chocolate
100 grams (3.5 oz, 1/3 cup + 1 tbsp) heavy cream
Marshmallow Creme/Fluff (homemade):
90 grams (1/3 cup, 3 oz) water
150 grams (3/4 cup) granulated sugar
250 grams (3/4 cup) agave syrup, honey, or corn syrup
1 teaspoon lemon juice or 1/2 tsp cream of tartar
3 large egg whites
1 teaspoon vanilla extract
More marshmallow creme or store bought marshmallow fluff to spread over cake (optional)

Instructions

Step 1: Preheat oven to 180 °C (350 °F). Grease and flour three 20 cm (8 inch) springform pans and line the bottoms with parchment paper.
Step 2: Using a food processor, pulse the digestive biscuits or graham crackers until finely ground. Add melted butter (and sugar if using graham crackers) and mix until combined. Divide this mixture evenly between two of the prepared pans, pressing it into an even layer to form the cookie crust. Refrigerate while preparing the batter.
Step 3: In a bowl, whisk together flour, cocoa powder, baking soda, baking powder, and salt.
Step 4: In a large bowl, beat eggs and sugar until pale. Add vanilla extract, oil, buttermilk, and hot coffee or water and mix well.
Step 5: Slowly add the dry ingredients to the wet ingredients using a mixer on low speed, mixing until combined. The batter will be thin.
Step 6: Pour the batter evenly into the three pans, making sure to pour it over the cookie crust in the two crusted pans.
Step 7: Bake for 20 to 30 minutes, or until a toothpick inserted into the center comes out clean. The pan without crust may bake faster, so remove it a few minutes earlier if needed.
Step 8: Cool cakes for 10 minutes, then remove from pans (leave the springform bottoms) and transfer to wire racks to cool completely before frosting.
Step 9: For the chocolate filling, place chopped chocolate in a heatproof bowl. Heat heavy cream until very hot (1-2 minutes in microwave) and pour over chocolate. Let sit 1-2 minutes, then stir slowly until smooth. Stir in butter until creamy. Let thicken at room temperature for 30 minutes.
Step 10: To make marshmallow buttercream, beat butter until smooth. Add powdered sugar, salt, and vanilla and beat until combined. Add marshmallow fluff and beat until fluffy, about 3 minutes.
Step 11: For chocolate ganache, repeat the heating and stirring method with chocolate and cream as above until smooth.
Step 12: To make homemade marshmallow creme (optional), whisk egg whites and lemon juice or cream of tartar to soft peaks. Meanwhile, heat water, sugar, and syrup until 120 °C (240 °F) without stirring. Slowly pour syrup into egg whites while mixing, then whip until thick and glossy, about 6-8 minutes. Add vanilla and cool.
Step 13: Level cake tops if needed. Place one cookie crust cake layer upside down on a plate. Spread one-third of the buttercream over the cookie crust and pipe a border around the edge. Fill with chocolate filling. Repeat with second cookie crust layer.
Step 14: Place final layer without cookie crust upside down on top. Spread remaining buttercream over top and sides.
Step 15: Refrigerate cake for 30 minutes before pouring ganache over. Spread or pipe marshmallow creme and toast with a kitchen torch until golden. Remove torch as soon as desired color is reached.

Tips & Variations

Use high-quality dark chocolate for both the filling and ganache to deepen the chocolate flavor.
Substitute regular sugar with coconut sugar in the cake for a more caramel-like note.
Try adding a pinch of cinnamon or espresso powder to the cake batter to enhance richness.
If you don’t have a kitchen torch, briefly place the marshmallow-topped cake under a broiler, watching carefully to avoid burning.
Make the marshmallow creme a day ahead to save time on assembly day.

Storage

Store the assembled cake in an airtight container or covered with plastic wrap in the refrigerator for up to 4 days. To keep the marshmallow topping fresh, avoid covering it tightly. Bring the cake to room temperature before serving for best texture. Reheat slices briefly in a microwave if desired, but do so gently to avoid melting the marshmallow topping.

How to Serve

A slice of three-layer chocolate cake sits on a white speckled plate, placed on a white marbled textured surface. The cake has dark, moist chocolate layers and between these are light brown crumbly layers. A thick layer of white frosting covers the sides and base of the slice, with parts of the frosting slightly toasted to a golden brown. The texture of the chocolate layers is dense and rich, while the frosting looks creamy and soft. A silver fork rests beside the slice on the plate, adding to the scene. In the background, another white plate holds similar cake slices, and a full cake is blurred. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I use regular sugar instead of powdered sugar in the buttercream?

Powdered sugar is best for smooth buttercream without grittiness, so it’s recommended to use it. Regular granulated sugar won’t dissolve properly and will affect texture.

Is it necessary to use coffee in the cake batter?

Coffee enhances the chocolate flavor but does not make the cake taste like coffee. You can substitute hot water if preferred, but coffee is recommended for the richest taste.