This s’mores layer cake features graham cracker–flavored cake layers filled with homemade marshmallow fluff, chocolate ganache, and finished with a chocolate Swiss meringue buttercream.
When I first posted this recipe years ago, the photos needed an update — but the cake itself was always worth sharing. One friend once joked after tasting it, “Is this girl married? Cuz if not, then all she needs to do to get married is bake this cake!” I’m happily married, but I’ll take that as a high compliment to the cake.
If you enjoy s’mores desserts, consider trying my other s’mores recipes: s’mores cupcakes, peanut butter s’mores cupcakes, baked s’mores donuts, s’mores cookies, s’mores cinnamon rolls, s’mores brownie ice cream, or a homemade s’mores frappuccino.
How To Make S’mores Cake, Step-By-Step Photos
Graham Cracker Cake
- Cream the butter with the granulated and brown sugars plus the oil until light and fluffy.
- Beat in the eggs one at a time, scraping the bowl as needed.
- Alternate adding dry and wet ingredients in several increments (begin and end with the dry ingredients) and mix until just combined.
- Bake the batter evenly in three 6-inch round pans until the cakes spring back to the touch. Cool completely before assembling.
Chocolate Ganache
Chocolate ganache is simply chocolate and heated cream. For a stable filling, cool the ganache to room temperature so it won’t run when you layer the cake. If you’re new to ganache, read a detailed guide on ganache ratios to find the best texture for your cake.
- Heat the cream until steaming and simmering but not boiling.
- Pour the hot cream over the chocolate and let it sit for a minute, then stir from the center outward until silky smooth.
- Cool completely to room temperature before using between cake layers.
Swiss Meringue / Marshmallow Fluff
This marshmallow-style Swiss meringue uses egg whites and sugar heated over a double boiler, then whipped to glossy, stable peaks. Using a thermometer ensures the sugar is fully dissolved and the meringue won’t weep.
- Whisk sugar and egg whites (with cream of tartar) over a double boiler until the sugar dissolves and mixture reaches 170°F (77°C).
- Transfer to a mixer and whip to stiff, glossy peaks — about 10 minutes. Fold in vanilla, then reserve half for the marshmallow filling.
- Use the remaining half to make the Swiss meringue buttercream by adding butter and other flavorings.
Chocolate Swiss Meringue Buttercream
The Swiss meringue base becomes chocolate Swiss meringue buttercream (SMBC) after folding in softened butter and a portion of the cooled ganache. Adding cocoa powder and a pinch of salt balances the sweetness and deepens the chocolate flavor.
- Beat butter into half of the meringue in small increments until the mixture emulsifies into a silky buttercream.
- Mix in HALF the cooled chocolate ganache so the buttercream maintains structure and chocolate richness without becoming too soft.
- Add cocoa powder and vanilla and blend until smooth and evenly colored.
Storing Cake with Meringue
Store the assembled cake at room temperature for up to one day if your kitchen is cool and the frosting remains firm. For longer storage, refrigerate the cake for up to a week. If you cut slices, cover the exposed sides with plastic wrap or place slices in an airtight container.
To freeze, wrap the whole cake tightly in plastic and foil or use a cake container, or freeze individual slices in airtight containers for a few weeks. Thaw to room temperature before serving for the best texture.
I hope you love this s’mores layer cake as much as I do. If you have questions, please leave a comment on the recipe post — comments are answered faster than email or social media. If you try the recipe, a 5-star rating or review is always appreciated.
Happy baking!
Love, B
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