Ultimate S’mores Layer Cake

Here is my favorite s’mores layer cake recipe, with fluffy chocolate cake layers, creamy marshmallow frosting, and a crunchy graham cracker crumb coating that tastes just like the campfire treat.

This s’mores cake is always a hit at birthday parties and family gatherings. I love making it because it brings back memories of summer camping trips, but you get to enjoy it indoors year-round. Plus, no sticky fingers from melted marshmallows!

s'mores layer cake
Image: theamazingfood.com / All Rights reserved

Why You’ll Love This S’mores Layer Cake

  • Nostalgic campfire flavors – This cake brings all the cozy memories of making s’mores around a campfire right to your kitchen, with layers of chocolate cake, marshmallow frosting, and graham cracker crunch.
  • Show-stopping dessert – The towering layers and classic s’mores toppings make this cake a real conversation starter that’s perfect for birthdays, gatherings, or any time you want to impress.
  • Rich chocolate cake base – The moist chocolate cake made with coffee and buttermilk creates the perfect foundation that’s way better than any boxed mix.
  • Fluffy marshmallow frosting – The marshmallow fluff frosting is like biting into a cloud and gives you that authentic s’mores taste without needing a campfire.
  • Fun to decorate – You get to play with mini marshmallows, chocolate squares, and graham crackers to make it look just like the real thing, which makes decorating almost as fun as eating it.

What Kind of Graham Crackers Should I Use?

For this s’mores layer cake, you’ll want to use regular honey graham crackers – the classic rectangular sheets that come in most grocery stores. Avoid the cinnamon or chocolate varieties since they’ll compete with the other flavors in your cake. Make sure your graham crackers are fresh and crispy, not stale, as they need to crush properly for the crust and maintain some texture for the garnish. You can use any brand you like, but I find that name-brand crackers tend to have a more consistent texture and better flavor than store brands.

s'mores layer cake
Image: theamazingfood.com / All Rights reserved

Options for Substitutions

This s’mores cake has some room for swaps, though a few ingredients are pretty essential for that classic campfire taste:

  • Graham crackers: These are really the star of the s’mores flavor, so I wouldn’t recommend substituting them. However, if you’re in a pinch, you could use digestive biscuits or vanilla wafers, though the taste will be different.
  • Buttermilk: No buttermilk? Make your own by adding 1 1/2 tablespoons of lemon juice or white vinegar to regular milk and let it sit for 5 minutes before using.
  • Hot coffee: The coffee brings out the chocolate flavor, but you can replace it with hot water or hot milk if you prefer. You could also use decaf coffee if caffeine is a concern.
  • Marshmallow fluff: This is pretty key for that s’mores taste, but if you can’t find it, you can make your own by melting mini marshmallows with a little water, or use marshmallow creme.
  • Milk chocolate: Feel free to use dark chocolate or semi-sweet chocolate if that’s what you have. You could even mix in some chopped chocolate bars for extra texture.
  • Vegetable oil: Canola oil, melted butter, or even applesauce (though this will change the texture slightly) can work as substitutes.

Watch Out for These Mistakes While Baking

The biggest mistake when making s’mores layer cake is adding the hot coffee too quickly to your chocolate batter, which can cause the eggs to scramble – instead, slowly stream in the coffee while mixing on low speed to keep everything smooth. Another common error is not letting your cake layers cool completely before frosting, as warm cake will melt your marshmallow buttercream and create a messy situation. When making the ganache, avoid pouring hot cream directly onto the chocolate all at once, which can cause it to seize – pour it gradually and stir gently from the center outward for a silky finish. Finally, don’t skip chilling the assembled cake for at least an hour before serving, as this helps all the layers set properly and makes slicing much cleaner.

s'mores layer cake
Image: theamazingfood.com / All Rights reserved

What to Serve With S’mores Layer Cake?

This cake is already pretty indulgent on its own, so I like to keep the sides simple and let it be the star of the show. A scoop of vanilla ice cream is always a good choice – it helps balance out all that rich chocolate and marshmallow sweetness. Cold milk is another classic pairing that works really well, especially if you’re serving this to kids who will definitely want something to wash down all that goodness. For adults, a cup of strong coffee or even hot chocolate can be a fun way to lean into the campfire theme, and the slight bitterness helps cut through the sweetness of the cake.

Storage Instructions

Keep Fresh: This s’mores layer cake is best stored covered at room temperature for up to 3 days. I like to use a cake dome or cover it loosely with plastic wrap to keep the marshmallow frosting from getting too sticky. The graham cracker layers might soften slightly over time, but that’s totally normal!

Refrigerate: If your kitchen is really warm or you need to keep it longer, pop it in the fridge for up to a week. Just bring it back to room temperature about 30 minutes before serving so the frosting gets nice and fluffy again. The chocolate ganache actually tastes amazing when it’s slightly chilled!

Make Ahead: You can definitely prep parts of this cake ahead of time. Bake the chocolate cake layers up to 2 days early and wrap them tightly in plastic wrap. The marshmallow frosting is best made the day you plan to assemble, but the chocolate ganache can be made a day ahead and gently rewarmed before using.

Preparation Time 30-45 minutes
Cooking Time 60-75 minutes
Total Time 90-120 minutes
Level of Difficulty Medium

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

  • Calories: 8000-8500
  • Protein: 60-70 g
  • Fat: 400-450 g
  • Carbohydrates: 900-950 g

Ingredients

For the graham crust:

  • 18 full sheets graham crackers (279 g)
  • 8 tbsp unsalted butter, melted (113 g)
  • 1/2 cup granulated sugar (99 g)

For the chocolate cake:

  • 2 3/4 cups all-purpose flour (330 g)
  • 3 cups granulated sugar (594 g)
  • 1 cup natural unsweetened cocoa powder (84 g)
  • 1 tbsp baking soda
  • 1 1/2 tsp baking powder
  • 1 1/2 tsp salt
  • 3 large eggs, room temperature
  • 1 1/2 cups buttermilk (340.5 g)
  • 1 1/2 cups hot coffee (340.5 g)
  • 3/4 cup vegetable oil (148.5 g)
  • 1 1/2 tbsp vanilla extract

For the marshmallow frosting:

  • 1 1/2 cups unsalted butter (339 g)
  • 7 cups confectioners’ sugar (794.5 g)
  • 10 oz marshmallow fluff (283.5 g)
  • 2 tsp vanilla extract
  • 1/2 tsp salt

For the chocolate ganache:

  • 7 oz milk chocolate, chopped (200 g)
  • 3/4 cup heavy cream (170.3 g)
  • Pinch salt

For the toppings:

  • Miniature marshmallows
  • Additional graham crackers
  • Milk chocolate squares

Step 1: Prepare the Cake Pans and Graham Cracker Crust

  • 18 full sheets graham crackers (279 g)
  • 8 tbsp unsalted butter, melted (113 g)
  • 1/2 cup granulated sugar (99 g)

Preheat your oven to 350°F (175°C).

Grease and flour three 8-inch round cake pans, or spray with nonstick baking spray.

Line each pan with parchment paper, then grease and flour or spray again.

To make the graham cracker crust, crush the graham crackers into fine crumbs using a food processor or by hand.

Combine the crumbs with melted butter and sugar in a large bowl, mixing until no dry clumps remain.

Divide this mixture among the three prepared pans and press into an even layer using a measuring cup, glass, or the back of a spoon.

Bake the crusts for 10 minutes, then set aside to cool completely.

Step 2: Make the Chocolate Cake Batter

  • 2 3/4 cups all-purpose flour (330 g)
  • 3 cups granulated sugar (594 g)
  • 1 cup natural unsweetened cocoa powder (84 g)
  • 1 tbsp baking soda
  • 1 1/2 tsp baking powder
  • 1 1/2 tsp salt
  • 3 large eggs, room temperature
  • 1 1/2 cups buttermilk (340.5 g)
  • 1 1/2 cups hot coffee (340.5 g)
  • 3/4 cup vegetable oil (148.5 g)
  • 1 1/2 tbsp vanilla extract

In a large bowl, use a mixer to combine the flour, sugar, cocoa powder, baking soda, baking powder, and salt.

In a separate bowl, whisk together the eggs, buttermilk, hot coffee, vegetable oil, and vanilla extract.

Add the wet ingredients to the dry mixture and mix on low speed until just combined, about 2 minutes.

The batter will be thin, which helps ensure the cake stays moist.

Step 3: Bake and Cool the Cake Layers

  • cake batter from Step 2
  • graham cracker crust lined cake pans from Step 1

Divide the cake batter evenly among the three pans over the cooled graham crust.

Bake for 35 minutes, or until a toothpick inserted in the center comes out with a moist crumb.

Cool the cakes in their pans for 20 minutes, then carefully turn them out onto wire racks to cool completely before assembling.

I always let my cake layers cool thoroughly to prevent the frosting from melting later.

Step 4: Make the Marshmallow Frosting

  • 1 1/2 cups unsalted butter (339 g)
  • 7 cups confectioners’ sugar (794.5 g)
  • 10 oz marshmallow fluff (283.5 g)
  • 2 tsp vanilla extract
  • 1/2 tsp salt

Cream the unsalted butter using an electric mixer on low speed until smooth.

Gradually add the confectioners’ sugar one cup at a time, mixing well between additions.

Once combined, mix in the marshmallow fluff, vanilla extract, and salt, and beat on medium-high speed for about 4 minutes until light and fluffy.

If the frosting becomes too warm or runny, refrigerate it for 5–10 minutes to thicken before using.

For an extra fluffy texture, I sometimes whip the frosting a few extra minutes at the end.

Step 5: Assemble and Frost the Cake

  • cake layers from Step 3
  • marshmallow frosting from Step 4

If needed, level the cooled cake layers.

Place one cake layer, graham cracker side down, on your serving plate.

Spread about 3/4 cup of frosting over the top.

Add the second layer and repeat the frosting process.

Place the final layer on top, face down, and use the remaining frosting to coat the sides and top of the cake.

Chill the cake to set the frosting before adding the final decorations.

Step 6: Prepare the Chocolate Ganache and Drip

  • 7 oz milk chocolate, chopped (200 g)
  • 3/4 cup heavy cream (170.3 g)
  • pinch salt

Heat the heavy cream in the microwave on 50% power in 30 second increments or on the stovetop just until it comes to a boil.

Place the chopped milk chocolate and a pinch of salt in a mixing bowl.

Pour the hot cream over the chocolate and let it sit for about 2 minutes to melt the chocolate.

Whisk gently from the center outwards until smooth and shiny.

Let it cool, whisking occasionally, until thickened but still pourable—about 10–15 minutes.

Transfer to a piping bag, snip off the corner, and drip the ganache along the edge of the cake, letting it run down the sides.

Pour the remaining ganache onto the center of the cake.

Step 7: Decorate the Cake with S’mores Toppings

  • miniature marshmallows
  • additional graham crackers
  • milk chocolate squares

Press graham crackers along the base of the cake.

Arrange miniature marshmallows around the top and, using a kitchen torch, lighter, or oven broiler, toast the marshmallows until golden and slightly melted.

Finish by pressing additional graham cracker squares and milk chocolate pieces into the melted marshmallows.

To make the cake truly indulgent, I love using an extra handful of mini marshmallows for that classic campfire vibe.

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