This s’mores cake, made with brown sugar cake, bittersweet chocolate frosting, toasted marshmallows, and graham cracker crumbs, is perfect for any special occasion.
Adapted from Caroline Wright | Cake Magic! | Workman Publishing Company, 2016
This whimsical s’mores cake elevates that classic campfire fix to superstardom. It’s made with two layers of brown sugar cake that are smothered with bittersweet chocolate frosting and topped with graham cracker crumbs and marshmallow topping. Certain to satisfy—with no panic about unexpected campfire pyrotechnics.–Angie Zoobkoff
For the s'mores cake
- Unsalted butter at room temperature, for the cake pans
- 2 1/2 cups all-purpose flour plus more for the pans
- 1 1/2 cups granulated sugar
- 1 teaspoon baking soda
- 3/4 teaspoon baking powder
- 1 teaspoon table salt
- 1/3 cup packed light brown sugar
- 2 sticks (8 oz) unsalted butter melted and cooled, or 1 cup (237 ml) vegetable oil
- 3/4 cup full-fat plain yogurt (not Greek yogurt)
- 2/3 cup cold water
- 1 tablespoon unsulfured molasses
- 1 teaspoon vanilla extract
- 4 large eggs at room temperature
For the syrup
- 1/2 cup granulated sugar
- 1/2 cup cold water
- Pinch of salt
- 1 tablespoon vanilla extract or the seeds scraped from 1 vanilla bean
For the bittersweet chocolate frosting
- 3 sticks (12 oz) unsalted butter at room temperature
- 2 tablespoons unsweetened cocoa powder
- Pinch of table salt
- 4 cups confectioners’ sugar
- 4 ounces unsweetened chocolate melted and cooled
For the marshmallow topping
- 2 cups miniature marshmallows
For the assembly
- Graham Cracker Crumbles (optional; see Variations below)
Make the s'mores cake
- Preheat the oven to 350°F (177°C).
- Generously butter two 8- or 9-inch (20- or 23-cm) round cake pans. Dust with flour and tap out any excess.
- In a large bowl, combine the flour, sugar, baking soda, baking powder, salt, and brown sugar.
- In another large bowl, stir together the butter, yogurt, water, molasses, vanilla, and eggs.
- Pour the dry ingredients into the wet and stir gently until no lumps remain. Be careful not to overmix. Divide the batter evenly between the prepared pans.
- Bake until the cakes are domed and a few moist crumbs cling to a tester inserted in the center of the cake, 30 to 35 minutes.
Make the syrup
- While the cakes bake, in a small saucepan over medium-high heat, combine the sugar, water, and salt and bring to a boil.
- Cook until the sugar is dissolved, 3 to 5 minutes.
- Stir in the vanilla and remove from the heat. Let cool. (If desired, cover and refrigerate for up to 1 week. Reheat gently before using.)
Soak the cake with syrup
- While the cakes are cooling in their pans, use a skewer or the tip of a paring knife to pierce them at 1-inch (2.5-cm) intervals.
- Gently pour or generously brush the syrup over the surface of the hot cake layers. Move the cakes, still in their pans, to a wire rack to cool and dry completely, about 2 hours.
- Run a knife around the sides of the cakes to loosen them. Carefully turn the cakes out of their pans and onto plates.
Make the bittersweet chocolate frosting
- In the bowl of a stand mixer fitted with the paddle attachment, beat the butter, unsweetened cocoa powder, salt, and 2 cups confectioners’ sugar on low speed until incorporated, 1 to 2 minutes.
- Add the remaining 2 cups sugar and beat on medium speed until the frosting is pale and no longer grainy, 2 to 3 minutes.
- In a slow, steady stream, drizzle in the melted chocolate and beat until the frosting is very light and fluffy, about 2 minutes. (You can cover and stash the frosting in the fridge for up to 1 week. Before using, return it to room temperature and stir or beat before using.)
Make the marshmallow topping
- Line a large rimmed baking sheet with parchment paper. Scatter the marshmallows on the prepared baking sheet and freeze until solid, about 10 minutes.
- Heat the broiler with the broiler rack set at least 8 inches (15 to 20 cm) from the element.
- Broil the marshmallows, watching them carefully and shaking the pan occasionally, until evenly golden brown and charred in spots, 1 to 2 minutes.
☞TESTER TIP: You’ll want to use a thin metal spatula to transfer the toasted marshmallows. If they stick to the baking sheet, pop everything in the freezer for a couple minutes.
Assemble the s'mores cake
- Using a serrated knife, slice the domed top from one of the cake layers so it’s flat. Place the cake on a plate or platter.
- Frost the top of the cake. If desired, sprinkle with graham cracker crumbles (about 3/4 cup).
- Carefully stack the second layer of cake on top of the first and frost the top and sides of the entire cake.
- Gently press graham cracker crumbles, if desired, onto the side of the cake so they’re evenly distributed.
- Use a thin metal spatula to arrange the toasted marshmallows on the top of the cake.
How to make the Graham Cracker CrumblesThese graham cracker crumbles are completely optional. Well, until you taste them. 2 sleeves graham crackers (about 18 sheets of crackers), finely crushed (about 2 cups/284 grams) 1/4 cup malted milk powder (35 g) 2 tablespoons granulated sugar (25 g) 1/2 teaspoon kosher salt 6 tablespoons unsalted butter (3 oz | 85 g), melted Preheat the oven to 300°F (150°C). Line a large rimmed baking sheet with parchment paper. In a large bowl, combine the graham cracker crumbs, malted milk powder, sugar, and salt and toss to thoroughly mix. Drizzle the melted butter over the crumb mixture and stir until clumps form. Scatter the clumps onto the prepared baking sheet in a single layer. Bake until the crumbles are golden brown and fragrant, 10 to 15 minutes. Let cool completely before using. You’ll have extra for snacking. This is a very good thing.
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Recipe Testers’ Reviews
This s’mores cake is not only fun (who doesn’t love s’mores??!!), all of the components come together really easily. The cake layers can be mixed by hand, the syrup can be made while the cake is baking, the crumbs baked while the cake is cooling and the frosting whips together in no time.
The cake was nice and moist from the syrup and the chocolate frosting was not sickeningly sweet. The graham crumbs add a fun crunch factor and you couldn’t call the cake s’mores without the broiled marshmallow. This is a fun recipe that would be great to bring out as the final note of a backyard barbecue.
I didn’t use all of the graham cracker crumbs. Probably used about half. I’m planning on using the rest in yogurt!
This s’mores cake is a great weekend project—the components are straightforward to make although putting them all together takes some time. In the end, you have a whimsical cake reminiscent of its fireside treat namesake that will delight a child (or the one in you).
The components taste delicious on their own AND in combination. The brown sugar cake is moist, tender, and spongy, especially with the added vanilla syrup. And it’s not too sweet, which is good because it plays off the chocolate frosting and marshmallows well. If you want a taller cake, use 8-inch pans. I used 9-inch pans and this produced squatter layers, but once you fill the cake with the frosting and the graham crackers, you’ll get an end result that is tall enough either way.
The added malt powder in the graham cracker crumbles really gives them a nice boost – you can detect it even if you aren’t aware of the ingredients. The chocolate frosting is a great consistency for easy spreading and decorating—it’s a bit sinful with the 4 cups of sugar. (I might be tempted to go down by a cup on the sugar or try a semi-sweet ganache frosting next time, but this one certainly works well).
As for the marshmallow topping, this is really the signature element to bring the cake into s’mores territory and was surprisingly the toughest to get right. My first round of marshmallows was too close to the broiler and got singed pretty quickly! I’d suggest watching them closely and making sure your marshmallows are about 8 inches from the broiler.
The frosting is somewhat stiff but spreads very easily. It’s a bit sweet but it works because the cake isn’t overly sweet.
I only used 1/2 cup of the crumbles in between the cakes. I used the finest pieces so that the second cake layer would sit level. I suggest spacing the marshmallows out so that you can easily slice the cake between them –cutting through the marshmallow is challenging as they’re gummy. For this reason, I suggest only using 1 1/2 cups marshmallows instead of 2 cups. This also worked out well for me because I don’t have a freezer with the capacity to place a whole sheet pan. Using 1 1/2 cups of marshmallows allowed me to fit them in an 8×8″ brownie pan. This cake is so rich I would say you’d get 16 good-sized servings.
If you make this recipe, snap a photo and hashtag it #LeitesCulinaria. We'd love to see your creations on Instagram, Facebook, and Twitter.
This s’mores cake is a showstopper! Beautiful to look at and it tastes even better. It does take a little while to put it all together, but it isn’t difficult, and the instructions are very clear.
I made everything except the marshmallow topping the day before serving, and the cake stayed very moist. It’s very rich. The graham crumbles were the star of the cake. Fantastic flavor! The recipe makes more crumble than needed, but it’s pretty tasty to just snack on.