Is this the ultimate homemade s’mores cake? I’ll let you be the judge! This s’mores cake is a decadent combination of moist chocolate cake, toasted marshmallow buttercream, graham cracker crunchies, and chocolate ganache. If you’re a s’mores lover, this layer cake is definitely for you!
When it comes to summer evenings, one of the best things is a warm, gooey s’more. The graham crackers, the chocolate, the toasty marshmallows… what’s not to love? In this s’mores cake, all those components come together with my best moist chocolate cake to make the most amazing cake inspired by the tasty classic campfire treat.
The final s’mores cake is truly a thing to behold. It’s beautiful on the outside and FULL of flavor on the inside. The recipe requires a few steps, but each layer is really quite simple to put together, and it comes together easily. It’s fun to make and will certainly impress a crowd. This is the perfect cake for summer, and I hope you enjoy it!
What You Can Expect From This S’mores Cake
- Moist chocolate cake. My original cake recipe (linked above) is an all-time favorite and has dozens of amazing reviews. It’s moisture and rich crumb make it perfect for layer cakes. I use the same base recipe for my s’mores cupcakes.
- Toasted marshmallow frosting. You can’t make a s’more without a toasted marshmallow! The frosting uses whole marshmallows toasted in the oven, cooled, and then broken apart to be added to the marshmallow fluff frosting. So good!
- Graham cracker crunchies. Graham cracker crumbs are combined with some sugar and melted butter and then toasted to create little crunchies.
- Chocolate ganache. Obviously, some form of melty chocolate needed to be included in this s’mores cake recipe. Homemade chocolate ganache is about as close as you get to the melted Hershey bar in the real thing!
Ingredient Notes
Let’s take a look at the key ingredients in this s’mores layer cake. The full recipe with exact measurements for each ingredient can be found in the recipe card at the end of the post.
- Flour – Make sure to measure the flour correctly using a kitchen scale, or the spoon and level method. Too much flour makes the cake dry.
- Cocoa powder – I recommend natural unsweetened cocoa powder in this recipe.
- Vegetable oil – For an ultra-moist, tender chocolate cake. Choose a neutral-flavored oil, like canola or vegetable oil.
- Hot water – Hot water “blooms” the cocoa powder and enhances the chocolate flavor in the cake.
- Graham crackers – I crushed up about 6 full graham cracker sheets to make 3/4 cup of crumbs. You’ll combine the crumbs with melted butter and sugar, similar the mixture in a graham cracker crust, to make the crunchies between the cake layers.
- Marshmallow Fluff – For the marshmallow frosting. I used nearly two full 7-ounce jars.
- Mini marshmallows – The marshmallows are toasted in the oven and added to the marshmallow frosting. They add some authentic toasted marshmallow flavor and a little bit of chewiness to the frosting.
- Chocolate chips – To melt with heavy cream for the chocolate ganache. Chocolate chips will work here, but for an extra-smooth ganache, use baking bars or similar.
- Frosting – I use vanilla buttercream to pipe a stable barrier around the outside edge of the cake, holding in the marshmallow frosting, ganache, and graham cracker layers inside. You can use any flavor of frosting for this.
How to Make a S’mores Cake, Layer By Layer
To start, you’ll prepare and bake the chocolate cake layers. It’s pretty much a one-bowl chocolate cake that comes together super quickly. All you really need is a whisk; no need to pull out the mixer. And don’t be afraid of the thin batter. It’s absolutely correct and makes the most wonderful chocolate cake.
Afterward, bake the cakes until a toothpick comes out clean, and let them cool before you assemble your s’mores cake.
Graham Cracker Crumbs
The next thing you’ll put together are the graham cracker crunchies:
- Combine. Mix together the crumbs, sugar and butter.
- Bake. Spread the crumbs out on a baking sheet. Bake for 8-10 minutes, cool, and you’re ready to go.
Marshmallow Frosting
Making the toasted marshmallow frosting is much like making any other buttercream, but perhaps even simpler.
- Toast the marshmallows. Place the marshmallows on a sheet pan under the broiler for a minute, or until browned.
- Make the frosting. Combine butter with marshmallow fluff and powdered sugar, then add the toasted marshmallows.
Chocolate Ganache
The chocolate ganache is next.
- Melt the chocolate. Heat the cream and pour it over the chocolate chips. Allow the heat from the cream to melt the chocolate.
- Whisk. Whisk until smooth, and you’ve got your ganache.
Assembling the Cake
Lastly, you’ll whip up a batch of vanilla frosting, and it’s time to build the s’mores cake! There are two filling layers between the three cake layers. It starts with a layer of ganache, then the toasted marshmallow frosting, and finally the graham cracker crumbs. All of that is held in place by a vanilla frosting dam.
What Does a Frosting Dam Do?
While the marshmallow buttercream is relatively thick, I wanted to ensure everything stayed in place and the cake remained stable. The best way to do this is by using a thick, stable frosting to create a dam around the outside edges of the cake layers. I talk more about cake dams in this post on how to build a cake if you’re interested in understanding that more.
How to Decorate a S’mores Cake
Once all the layers are together, frost the outside of the cake with the remaining marshmallow frosting (see how to frost a smooth cake). To decorate:
- Make a skirt of graham cracker crumbs. Press any remaining graham cracker crunchies around the bottom of the cake.
- Pour over the ganache. Add your chocolate drip using the remaining chocolate ganache.
- Add more toasted marshmallows. The finishing touch is to add the toasted marshmallows around the top of the cake and use a kitchen torch to toast them (I use this butane torch).
Proper Storage
- Room temperature. This s’mores cake can be stored covered at room temperature for up to 2 days. Keep it in a cake carrier or another airtight container.
- Refrigerate. You can also keep the finished cake in the fridge for 3-4 days. I still recommend taking it out of the fridge 30 minutes or so before serving, so it can come back to room temperature.
More S’mores Desserts to Love
S’mores Cake
- Prep Time: 2 hours
- Cook Time: 40 minutes
- Total Time: 2 hours 40 minutes
- Yield: 12–14 slices 1x
- Category: Dessert
- Method: Oven
- Cuisine: American
Description
This s’mores cake is an amazing combination of moist chocolate cake, toasted marshmallow buttercream, graham cracker crunchies and chocolate ganache! If you’re a s’mores lover, this cake is definitely for you!
Ingredients
Chocolate Cake
- 2 cups (260g) flour
- 2 cups (414g) sugar
- 3/4 cup (85g) natural unsweetened cocoa powder
- 2 tsp baking soda
- 1 tsp salt
- 2 large eggs
- 1 cup (240ml) milk
- 1 cup (240ml) vegetable oil
- 1 1/2 tsp vanilla
- 1 cup (240ml) hot water
Graham Cracker Crunchies
- 3/4 cups (100g) graham cracker crumbs (about 6 full sheet graham crackers)
- 1 1/2 tbsp (20g) sugar
- 1/4 cup (56g) unsalted butter, melted
Toasted Marshmallow Frosting
- 1 3/4 cups (392g) unsalted butter, room temperature
- 3 1/4 cups marshmallow fluff*
- 6 cups (690) powdered sugar
- 1 1/2 cups mini marshmallows
Chocolate Ganache
- 9 oz (1 1/2 cups) semi-sweet chocolate chips
- 3/4 cup (180ml) heavy whipping cream
Vanilla Frosting
- 3/4 cup (168g) unsalted butter, room temperature
- 3 cups (345g) powdered sugar
- 1 tsp vanilla extract
- 1 tbsp milk or cream
Instructions
Make the chocolate cake:
- Prepare three 8 inch cake pans with parchment paper circles in the bottom, and grease the sides. Preheat oven to 300°F (148°C).
- Add all dry ingredients to a large bowl and whisk together.
- Add eggs, milk and vegetable oil to the dry ingredients and mix well.
- Add vanilla to boiling water and add to mixture. Mix well. The batter will be very thin.
- Divide batter evenly between cakes pans and bake for 30-33 minutes, or until a toothpick comes out with a few crumbs.
- Remove cakes from oven and allow to cool for about 5 minutes, then remove to cooling racks to cool completely.
Make the graham cracker crunchies:
- When the cakes are cooled and you’re ready to build the cake, preheat oven to 350°F. Line a cookie sheet with parchment paper or a silicone baking mat and set aside.
- Combine the graham cracker crumbs, sugar and melted butter and stir until well combined. Spread the crumbs evenly onto the prepared cookie sheet.
- Bake for 8-10 minutes, then allow to cool. Set aside.
Make the toasted marshmallow frosting:
- To make the frosting, toast the marshmallows under the broiler for about 1 minute, or until toasted. Remove from the oven and set aside to allow them to cool completely.
- Add the butter to a large mixer bowl and beat until smooth.
- Add the marshmallow fluff to the butter and beat until well combined.
- Add about half of the powdered sugar to the butter mixture and mix until well combined and smooth.
- Add the remaining powdered sugar and mix until well combined and smooth.
- Add the cooled toasted marshmallows and mix until well combined. If the marshmallows are quite sticky, break them apart into smaller pieces before adding them to the frosting. Set aside.
Make the chocolate ganache:
- Add the chocolate chips to a medium sized bowl.
- Heat the heavy whipping cream until it just begins to boil, then pour it over the chocolate chips.
- Allow the chocolate and cream and to sit for 3-5 minutes, then whisk together until smooth. Set aside.
Make the vanilla frosting:
- Add the butter to a large mixer bowl and beat until smooth.
- Add about half of the powdered sugar and mix until well combined and smooth.
- Add the vanilla extract and cream and mix until well combined.
- Add the remaining powdered sugar and mix until well combined and smooth.
Build the cake:
- Remove cake domes from the tops of the cake with a large serrated knife. See my tips on how to level a cake and how to stack a cake.
- Place the first layer of cake on a cake plate or cardboard cake circle. Pipe a dam of vanilla frosting around the outer edge of the cake. This dam will help keep all of the filling in place so that nothing seeps out or doesn’t stay in place.
- Add about 6 tablespoons of chocolate ganache to the top of the cake and spread it into an even layer.
- Add one cup of marshmallow frosting to the top of the ganache and spread into an even layer.
- Add 1/2 a cup of graham cracker crunchies to the top of the frosting and spread evenly.
- Add the second layer of cake, another dam of vanilla frosting, then another layer of ganache, marshmallow frosting and graham cracker crunchies.
- Top the cake with the final layer of chocolate cake. Refrigerate the cake for about 30 minutes or so to make sure everything is stable.
- Use the remainder of the marshmallow frosting to frost the outside of the cake. Feel free to use my tutorial for frosting a smooth cake.
- Press the remaining graham cracker crunchies into the bottom part of the cake.
- Use the remainder of the chocolate ganache to add the chocolate drip to the cake. See my tutorial for how to make a chocolate drip cake. It will have cooled off by now, so you’ll want to carefully heat it back up in the microwave.
- Add some mini marshmallows to the top of the cake and use a kitchen torch to toast them.
- Refrigerate cake until ready to serve. Cake is best when stored in an air tight container. Serve cool, but not cold and finish leftovers within 3-4 days.
Notes
*I used almost all of two 7 oz jars of marshmallow fluff
Nutrition
- Serving Size: 1 Slice
- Calories: 1193
- Sugar: 133.9 g
- Sodium: 412.5 mg
- Fat: 61 g
- Carbohydrates: 164.4 g
- Protein: 6.6 g
- Cholesterol: 130.1 mg
Enjoy!
Marshmallow buttercream modified from Cookies and Cups
I have had so many compliments on this cake! Great recipe!
My family loves his cake. I’ve made it several times. Planning on making it to take to the river.How many hours can the cake stay out of the refrigerator?
Technically, buttercream can sit at room temperature for up to 2 days. But I’m not sure what you are doing by the river. Will it be outside? Because that would definitely affect how long it could sit out.
I’m so glad you enjoy the cake!
What if I don’t have in my country marshmallow fluff? 😩
Hmm, you could make a regular buttercream and still add the toasted marshmallows. You could also try making a meringue frosting, like on this baked alaska.