Ultimate S’mores Cake – Layers of graham cracker crust, chocolate cake, chocolate ganache, toasted marshmallow filling, chocolate frosting and marshmallow fluff truly make this the ultimate s’mores cake!
My Love for S’mores Cakes
This post is a long time coming! I’ve diligently been testing different s’mores cake recipes for years now. Seriously! It’s been a personal mission of mine to find (what I consider) the best one. The first s’mores cake I made was Sweetapolita’s original Campfire Delight Cake, made up of dark chocolate cake layers, toasted marshmallow filling and malted chocolate frosting. To this day, it’s one of my favorite cakes, but it didn’t have a graham cracker element to it, which I felt was crucial to a s’mores cake. (In her new cookbook, “Sweetapolita Bakebook,” she made some revisions and the new recipe has graham cracker crumbs in between the layers!)
Over the last few years, I’ve tried several s’mores cake recipes, some with chocolate cake layers, some with vanilla cake layers, and some with graham cracker cake layers. I was always so excited to try the graham cracker cake layers, but was always so disappointed because the flavor and texture were always underwhelming.
I also tried a couple recipes that had toasted graham cracker crumbs in between each of the layers, but was disappointed in how quickly the graham crackers would get soggy.
Time for a Cake by Courtney S’mores Cake
Since I hadn’t found a single s’mores cake that rocked my world, I decided to create my own, inspired by some of my favorite elements from the cakes I had tried. One of these components was the Toasted Marshmallow Frosting from Sweetapolita’s Campfire Delight Cake. You guys! It’s unreal! You broil marshmallows in your oven until they’re golden brown, and then, once they’ve had a few minutes to cool, you add the toasted marshmallows to butter, powdered sugar and marshmallow cream. Unreal, right?
The next element I wanted to incorporate was the graham cracker. To make sure it wouldn’t get soggy, I decided to put a graham cracker crust on each layer that gets baked on its own before adding the cake batter. After the crust bakes, you just pour the chocolate cake batter right into the pans with the crust and bake again. This technique works perfectly for keeping the graham crackers crunchy.
I then decided to cover the entire cake with a silky chocolate buttercream, chocolate ganache drip, and a homemade marshmallow fluff, toasted with a kitchen torch.
So, in case I lost you, here’s how the cake stacks up: toasted graham cracker crust, dark chocolate cake layers, chocolate ganache, toasted marshmallow filling, chocolate frosting and marshmallow fluff. Is your mouth watering yet? I hope so!
All the ingredients and instructions are below. This cake definitely has a few more steps than your ordinary cake, but this cake isn’t just any ol’ cake. It’s the Ultimate S’mores Cake! Just give yourself enough time to make all the elements or spread it out over a couple days. And make sure to watch my quick time-lapse video to see how I assembled it all.
2cups(240 g) graham cracker crumbs, about 18 rectangular crackers (this is best done in a food processor or blender, but can be done by placing the graham crackers in a zip-lock bag and rolling over the crackers with a rolling pin)
1/2cup(113 g) unsalted buttermelted
1/3cup(70 g) granulated sugar
FOR THE CAKE
1 3/4cups plus 2 tablespoons (225 g) all-purpose flour
2cups minus 2 tablespoons (375 g) granulated sugar
3/4cups(88.5 g) dark cocoa powder
2teaspoons(8 g) baking soda
3/4teaspoon(3 g) baking powder
1teaspoon(5.6 g) salt
1cup(240 g) buttermilkat room temperature
1/2cup(109 g) vegetable oil
3large eggsat room temperature
1teaspoon(4.2 g) pure vanilla extract
1cup(236.6 g) hot water
FOR THE MARSHMALLOW FILLING, adapted from Sweetapolita
24large white marshmallows
1cup(125 g) powdered sugarmeasured and then sifted
1cup(226 g) unsalted butterat room temperature
1/2teaspoon(2.1 g) pure vanilla extract
1jar(200 g) marshmallow fluff
FOR THE GANACHE
1cup(150 g) semi-sweet or dark chocolate chips
1/2cup(115.5 g) whipping cream
FOR THE BUTTERCREAM
2cups(452 g) unsalted butterslightly chilled
5cups(625 g) powdered sugarmeasured and then sifted
1tablespoon(4.2 g) pure vanilla extract
10oz.good quality chocolateI use semi-sweet or dark chocolate, chopped, melted and cooled
1/3cup( 77 g) heavy whipping cream
*This buttercream recipe makes enough to fill and cover your cake. If you want to add additional pipingyou’ll want to make an extra 1/2 batch.
FOR THE MARSHMALLOW FLUFF
3egg whitesroom temperature
1/4teaspoon(1.4 g) salt
1/3cup(66.6 g) sugar
1cup(300 g) light karo syrup
2tablespoons(29.6 g) water
1tablespoon(12 g) vanilla bean paste or clear vanilla extract
FOR THE CRUST
Preheat your oven to 375 degrees F. Spray three 8-inch or four 6-inch round cake pans with non-stick spray and then line with parchment. Spray again. Set aside.
In a medium sized bowl combine the graham cracker crumbs, melted butter and sugar. Stir until all the graham cracker crumbs are damped by the melted butter.
Divide evenly between the three pans and press down firmly with your hand or the back of a spoon.
Bake for 5 to 7 minutes, until golden brown. Let cool while you make the chocolate cake batter.
FOR THE CAKE
Preheat the oven to 350 degrees F.
Combine the flour, sugar, cocoa, baking soda, baking powder, and salt into the bowl of an electric mixer fitted with a paddle attachment and mix on low speed until combined.
In another bowl, combine the buttermilk, oil, eggs, water and vanilla.
With the mixer on low speed, slowly add the wet ingredients to the dry, scraping the bottom of the bowl with a rubber spatula.
Pour the batter into the prepared pans (about 12 ounces in each 6-inch pan or 15 ounces in each 8-inch pan), over the cooked graham cracker crusts and bake for 18-20 minutes, until a toothpick inserted in the center of the cake comes out almost clean.
Cool in the pans for 10 minutes, then turn them out onto a cooling rack and cool completely.
Wrap in plastic wrap and chill until ready to use.
FOR THE MARSHMALLOW FILLING
Place the marshmallows on a cookie sheet lined with parchment paper and sprayed with nonstick cooking spray. Place on the middle rack of the oven, and broil the marshmallows until golden brown on top, about 30-60 seconds. Keep your eye on them!
Remove the pan from the oven and gently turn the marshmallows over and broil them again until they are golden brown on the other side.
In the bowl of a stand mixer fitted with the paddle attachment, combine the butter and powdered sugar and beat on low until blended. Add the vanilla and mix on medium speed for about three minutes
With the mixer on low speed, add the marshmallow cream and (cooled) toasted marshmallows, and mix for about one minute.
FOR THE GANACHE
In a microwave safe bowl, pour the cream over the chocolate chips and heat for about 45-60 seconds. Stir, and if needed, heat for another 30 seconds to melt the chocolate chips completely. Let cool to room temperature before using.
FOR THE FLUFF
In the bowl of a standing mixer, whisk the eggs and salt until fluffy and frothy.
Meanwhile, heat the sugar, corn syrup, water and vanilla paste. Heat over medium flame until the sugar is dissolved and just simmering, about 5 minutes.
With the mixer on medium speed, add a tiny bit of the hot sugar mixture to the egg whites at a time. (Temper the eggs - don't scramble the them)
Eventually, all of the sugar will be added and then turn the mixer up to high. Beat the mixture on high for about 5 minutes or until very stiff and shiny.
Best used right away.
FOR THE BUTTERCREAM
In the bowl of a stand mixer fitted with the paddle attachment, beat the butter until smooth and light in color, about 2 minutes.
With the mixer on low speed, gradually stream in the melted chocolate. Scrape down the sides of the bowl and mix for another minute.
Gradually add the powdered sugar, one cup at a time, followed by the salt and vanilla.
Add the heavy cream and then turn the mixer to medium-high speed and beat for 5 minutes.
Frosting can be store in an airtight container in the refrigerator for a week.
When you're ready to frost the cake, bring the frosting back to room temperature and mix by hand with a wooden spoon to push out all of the air pockets.
Level each chocolate cake layer, if needed, and then place the first cake layer, graham cracker side down, on a cake board.
Spread half of the chocolate ganache on the cake layer and then freeze for 5 to 10 minutes to set the ganache a little.
Carefully spread half of the toasted marshmallow filling over the chocolate ganache and repeat step 2 and 3 for the second cake layer.
Place the final cake layer, graham cracker side down, on top and cover with a crumb coat layer of the chocolate frosting. Freeze the cake for 10 to 15 minutes to set the crumb coat.
Finish frosting the cake with the chocolate frosting and then decorate the top of the cake with the marshmallow fluff, toasting with a kitchen torch, if desired.