S’mores Cake with Toasted Marshmallow and Chocolate

S’mores Cake: a homemade graham cracker cake topped with an easy marshmallow frosting studded with mini chocolate chips, finished with a soft chocolate ganache glaze. No campfire required—perfect for birthdays, parties, or holidays.

This S’mores Cake started as an idea and turned into something everyone in my kitchen loved. It combines a graham cracker-flavored cake base, a creamy marshmallow frosting with mini chocolate chips for texture, and a silky chocolate ganache poured on top. The result is a layered dessert that truly tastes like a cake version of the classic campfire s’more.

What are S’mores

For readers unfamiliar with the treat: a s’more is traditionally made by toasting a marshmallow over a fire and sandwiching it with a piece of chocolate between two graham crackers. The heat melts the chocolate and softens the marshmallow, creating an indulgent, gooey combination. This cake captures those flavors without needing an open flame.

(Printable recipe card and measurements are included below.)

This cake is straightforward to make, though it involves several steps and a little chilling time between layers. It’s baked in a 13×9-inch pan, so it serves a crowd—great for potlucks and gatherings. Take your time and allow each layer to cool or set before adding the next to preserve clean layers and texture.

S’mores Cake Ingredients (Graham Cracker Cake)

• Graham cracker crumbs (about 20 whole sheets, crushed)
• All-purpose flour
• Baking powder
• Baking soda
• Salt
• Unsalted butter, softened
• Granulated sugar
• Large eggs
• Vanilla extract
• Buttermilk (or homemade sour milk—see notes)

How to Make the Graham Cracker Cake

1. PREHEAT: Heat the oven to 350°F. Lightly grease and flour a 13×9-inch baking pan or line it with parchment paper.
2. DRY INGREDIENTS: In a bowl, whisk the graham cracker crumbs with flour, baking powder, baking soda, and 1/4 teaspoon salt until evenly combined.
3. WET INGREDIENTS: In a large bowl, cream 3/4 cup softened butter with 1 cup granulated sugar until light. Beat in the eggs one at a time, then stir in 2 teaspoons vanilla. Alternate adding the buttermilk and the dry mixture, beginning and ending with the buttermilk, mixing until just combined.
4. BAKE: Spread the batter evenly in the prepared pan and bake 25–35 minutes, until the top is golden and a toothpick inserted in the center comes out clean. Cool completely on a wire rack before frosting.

Marshmallow Frosting Ingredients

• Marshmallow fluff (not whole marshmallows)
• Unsalted butter, softened
• Vanilla extract
• Salt
• Confectioners’ (powdered) sugar
• Milk (as needed)
• Mini semi-sweet chocolate chips (or chopped chocolate)

How to Make the Marshmallow Frosting

1. COMBINE: With the cake fully cooled, beat together 16 ounces marshmallow fluff and 1 cup softened butter until smooth. Add 1 teaspoon vanilla and 1/4 teaspoon salt.
2. FINISH: Mix in about 4 cups confectioners’ sugar until the frosting comes together. If it seems too thick, add milk 1 tablespoon at a time until spreadable. Fold in one bag (about 10 ounces) of mini semi-sweet chocolate chips.
3. CHILL: Spread an even layer over the cooled cake and chill until the frosting is slightly firm, 30–60 minutes.

Chocolate Ganache Glaze Ingredients

• Mini semi-sweet chocolate chips or chopped semi-sweet chocolate
• Heavy whipping cream

How to Make the Chocolate Ganache Glaze

1. HEAT CREAM: Place the chocolate chips in a medium bowl. Heat 3/4 cup heavy cream until it just begins to boil.
2. MAKE GANACHE: Pour the hot cream over the chocolate and let sit 5 minutes, then stir until smooth and glossy. Cool until the ganache is still pourable but cool to the touch, 5–10 minutes.
3. GLAZE: Pour the ganache over the chilled marshmallow-frosted cake and spread evenly with a spatula. Let the ganache set until firm but slightly soft to the touch, about 30 minutes.

Serving and Storage

• Serve at room temperature, or chill for a firmer, fudgier ganache. Small slices are recommended—this cake is rich and sweet.
• Store covered at room temperature for a few days, or refrigerate for a firmer topping. The cake can also be frozen if wrapped well.

Quick Tips

• Make sure each layer is completely cool before adding the next to prevent melting or sliding.
• Substitute chopped dark or bittersweet chocolate for the chips if you prefer less sweetness; avoid milk chocolate, which may be overly sweet with the marshmallow frosting.
• Do not substitute whole marshmallows for marshmallow fluff in the frosting; the texture and consistency will differ.

Recipe Summary

Yield: one 13×9-inch cake (about 24 servings). Prep time: ~45 minutes. Cook time: ~35 minutes. Chilling and setting time: about 2 hours. Total time: roughly 3 hours.

Notes

To make a buttermilk substitute, add 4 teaspoons white distilled vinegar to a measuring cup, then add milk to reach 1 1/4 cups and let sit 5–10 minutes before using. If you want a less-sweet cake, reduce the frosting or use darker chocolate for the glaze.

Enjoy this S’mores Cake with coffee, hot chocolate, or a favorite dessert drink. It’s a crowd-pleaser that brings the classic campfire flavors to the table in cake form—no fire required.