This s’mores cake is made with moist chocolate cake layers baked over a buttery graham cracker crust, then filled with toasted meringue buttercream and rich chocolate ganache.

It has everything I love about a classic s’more, including crisp graham crackers, gooey marshmallow, and plenty of chocolate. But somehow, it’s even better in cake form!

This S’mores Cake at a Glance

• Yield: One 3-layer, 8-inch cake
• Serves: About 24
• Cake layers: Moist chocolate cake baked directly over a graham cracker crust
• Filling: Milk chocolate ganache and toasted meringue buttercream
• Skill level: Intermediate
• Make ahead: Yes! I highly recommend making the components in stages.
• Special equipment: A kitchen torch creates the signature toasted marshmallow flavor, and an instant-read thermometer helps ensure the meringue reaches 160°F/71°C.

How to Make This S’mores Cake

To make sure this cake turns out as amazing as possible, let’s walk through each step together!

I highly recommend reading through the entire recipe before you start. There are several components, and a little planning makes this cake so much easier to tackle.

Step 1: Make the Chocolate Ganache Filling

I recommend making the ganache first because it needs time to cool and thicken. I usually make it the night before, but you can also make it a few hours in advance.

Heat the heavy cream until it just begins to bubble and steam, then pour in the milk chocolate chips. Make sure the chocolate is fully covered by the cream and let the mixture sit for about a minute.

Slowly stir until the chocolate and cream come together into a smooth, glossy mixture.

Mix in the room-temperature butter, optional corn syrup, and salt. The corn syrup helps make the ganache extra smooth and glossy, but the recipe will still work without it.

Cover the ganache with plastic wrap and let it cool to room temperature. If you’re short on time, pour it into a shallow container so it cools more quickly.

My biggest tip here is not to rush the cooling process. Warm ganache is too fluid to use as a cake filling and can make the layers slide.

Step 2: Make the Graham Cracker Crust

Preheat your oven to 350°F/175°C and prepare three 8-inch cake pans with parchment paper rounds and nonstick spray.

Mix the graham cracker crumbs, melted butter, granulated sugar, and salt until evenly combined.

Divide the mixture between the prepared pans and press it firmly into an even layer. Bake the crusts for 8 to 10 minutes, then set them aside to cool slightly.

I love baking the chocolate cake directly on top of the crust. It makes each layer feel like an actual s’more and ensures you get graham cracker flavor in every bite.

Step 3: Bake the Chocolate Cake Layers

Next, make the chocolate cake batter following the recipe card at the bottom of this post.

Whisk the dry ingredients together in one bowl and the wet ingredients together in another. Add the dry ingredients to the wet ingredients and mix just until the batter is smooth and combined.

Divide the batter evenly between the three prepared pans, pouring it directly over the baked graham cracker crusts.

I recommend using a kitchen scale and adding about 475g of batter to each pan. This helps the cake layers bake to the same height and makes the finished cake easier to stack.

Bake for 24 to 27 minutes, or until a toothpick comes out with a few moist crumbs. Let the pans cool for 10 minutes, then run a small offset spatula around the edge of each pan.

Place the cake pans in the freezer for about 30 minutes to speed up the cooling process. This helps lock in steam and keeps the cake layers extra moist.

If you don’t have room in your freezer, let the cake layers cool completely on a wire rack before removing them from the pans.

Once the layers are fully cooled, carefully remove them from the pans. These cake layers usually bake up pretty flat, so leveling them is optional. However, I like to trim them with a serrated knife if needed to make the cake easier to stack and fill.

Step 4: Make the Meringue Base

While the cake layers cool, make the toasted meringue. Before you start, thoroughly clean and dry your mixing bowl and whisk. Even a small amount of grease can make it difficult for the egg whites to whip properly.

Add about an inch of water to a medium saucepan and bring it to a gentle simmer.

Combine the egg whites, granulated sugar, and light corn syrup (optional) in a large heatproof metal bowl, then place the bowl over the saucepan. The bowl should sit over the pot without touching the simmering water.

Whisk the mixture constantly until it reaches 160°F/71°C. The sugar should be completely dissolved. You can carefully rub a tiny bit of the mixture between your fingertips to check. It should feel smooth rather than grainy.

Transfer the mixture to the bowl of a stand mixer and whip on medium-high speed for about 10 minutes, or until stiff, glossy peaks form. The meringue should also cool back down before you add the butter later.

One of my favorite tricks is to place something cold around the base of the mixing bowl while the meringue whips. A bag of frozen vegetables works surprisingly well! This helps the meringue cool more quickly and can prevent the buttercream from becoming soupy.

Step 5: Toast the Meringue

Then comes the fun part! Use a kitchen torch to carefully toast the surface of the meringue directly in the bowl. Turn the mixer back on briefly to incorporate those toasted bits.

Repeat this process a few times until you can see small flecks of toasted meringue throughout the mixture.

This is what gives the buttercream its roasted marshmallow flavor, so don’t skip it!

Step 6: Mix in the Butter

Gradually mix the room-temperature butter into the meringue, along with the vanilla extract and salt. Once all the butter has been incorporated, the frosting should look thick, smooth, and fluffy.

At first, the frosting might look slightly broken or lumpy. Don’t panic! Keep mixing. Meringue-based buttercream often goes through an awkward stage before coming together. It should look fluffy and thick once it’s done mixing.

How to Assemble This S’mores Cake

Once all the components are ready, it’s time to put everything together!

Stack and frost the cake layers on a greaseproof cake board or large flat plate. Use a small dab of frosting to help stick the first cake layer to the board.

Step 1: Add the Chocolate Ganache

Place the first cake layer on the board. Spread half of the thickened chocolate ganache over the cake layer.

Make sure the ganache has cooled enough to hold its shape. If it’s still runny, let it sit longer before assembling the cake.

Step 2: Add the Toasted Meringue Buttercream & Repeat

Then spread a thick layer of toasted meringue buttercream on top of the ganache. Try to keep the filling relatively even so the next cake layer sits flat.

Add the second cake layer and repeat this process, then place the final cake layer on top.

Step 3: Chill and Frost the Cake

If the cake feels soft or unstable after stacking, chill it before frosting.

I recommend placing it in the freezer for about 20 minutes or in the fridge for 30 minutes. This gives the fillings time to firm up and helps prevent the cake layers from shifting.

Use the remaining buttercream to cover the cake in a thick layer of toasted meringue buttercream. Use a large offset spatula or the back of a spoon to create a textured look around the cake.

Step 4: Marble Some Melted Chocolate Into the Buttercream

If desired, drizzle the melted and cooled milk chocolate over the frosted cake while it is at room temperature but still fluid. Use the back of a spoon or an offset spatula to gently swirl it into the buttercream for a marbled finish.

Troubleshooting the Toasted Meringue Buttercream

Meringue-based frostings can look intimidating, but most problems come down to temperature.

Why Won’t My Meringue Whip to Stiff Peaks?

The most common culprit is grease. Make sure the mixing bowl and whisk attachment are completely clean and dry. Even a small amount of fat or egg yolk can prevent the whites from whipping properly.

Also, make sure the sugar is fully dissolved before whipping. The egg white mixture should reach 160°F/71°C and feel completely smooth when rubbed carefully between your fingertips.

Finally, be patient. It can take around 10 minutes for the mixture to become thick, glossy, and stiff.

Why Is My Buttercream Soupy?

Usually, the meringue was still too warm when the butter was added. The whipped meringue should cool close to room temperature first. If the bowl still feels warm, keep mixing or place something cold around the outside of the bowl.

If your finished buttercream is soupy, chill it briefly, then mix again.

Why Does My Buttercream Look Curdled or Broken?

This usually means the ingredients are at different temperatures. Keep mixing first. Often, the buttercream will come back together on its own after several minutes.

If it still looks broken, the temperature is usually the issue. A very cold buttercream may need gentle warmth, while a very soft buttercream may need a short chill before being mixed again.

Substitutions and Swaps

This recipe has several components, so I know you might not have every ingredient on hand. Below are the swaps I’d recommend.

Chocolate Cake Layers

• All-Purpose Flour: This recipe turns out best with all-purpose flour. However, you can use a good gluten-free 1:1 baking flour blend if needed. I recommend mixing the batter slightly longer and letting it rest for about 20 minutes before baking when using a gluten-free blend.
• Granulated Sugar: I don’t recommend reducing the sugar or changing the type of sugar. Sugar affects both the moisture and texture of the cake layers.
• Unsweetened Cocoa Powder: I usually use Ghirardelli or Hershey’s unsweetened cocoa powder. Dark cocoa powder can also be used.
• Buttermilk: Full-fat yogurt, sour cream, whole milk, or a nondairy milk can be used in its place.
• Vegetable Oil: Any neutral-flavored oil will work. Canola or sunflower oil are great alternatives. I don’t recommend olive oil because its flavor can come through in the finished cake.
• Eggs: This recipe turns out best with large eggs. If needed, you can experiment with a commercial egg replacer, but the texture may differ.

Milk Chocolate Ganache

• Milk Chocolate: I love milk chocolate here because it gives the cake that classic s’mores flavor. If you prefer dark chocolate, use 1 1/3 cups or 240g dark chocolate chips with 1 cup of heavy cream instead of the milk chocolate ratio in the recipe card.
• Corn Syrup: This is optional. It makes the ganache extra smooth and glossy, but can be omitted.
• Unsalted Butter: Salted butter can be used if needed. Reduce or omit the additional salt to taste.

Toasted Meringue Buttercream

• Unsalted Butter: Salted butter can be used in the buttercream, but I recommend reducing the added salt.

Making This S’mores Cake in Different Sizes

One batch of chocolate cake batter makes three 8-inch cake layers, with about 475g of batter per pan.

Because this uses the same chocolate cake base as my other layer cakes, you can also use the batter to make:

• Two 9-inch cake layers
• Four 6-inch cake layers

The bake time will vary depending on the size and depth of your cake pans, so use the visual cues in the recipe rather than relying only on the timer.

For any alternate size, divide the graham cracker crust evenly between the pans before adding the cake batter.

Because this cake has both ganache and toasted meringue filling, keep in mind that smaller-diameter cakes can become very tall. Chill the cake well during assembly if needed.

Can This S’mores Cake Be Made in Advance?

Yes! In fact, I highly recommend making this cake in stages.

There are several components, and trying to make everything in one sitting can feel like a lot.

Chocolate Ganache

The ganache is one of the best components to make ahead.

It needs at least an hour to cool and thicken, and I often make it the night before. Store it covered in the fridge, then let it soften until it reaches a spreadable consistency before assembling the cake.

Chocolate Cake Layers

The cake layers can be baked in advance and frozen. Once they’re fully cooled, wrap them tightly and freeze until needed. Let them thaw for about 15 minutes before assembling the cake.

I actually prefer stacking cake with slightly chilled layers because they’re easier to handle and create fewer crumbs.

Toasted Meringue Buttercream

The frosting can also be made ahead of time and stored in an airtight container in the fridge. Let it return to room temperature, then mix it again until smooth before using.

Assembled Cake

A fully frosted cake can be stored in the fridge for up to a week. Let the cake sit at room temperature before serving so the buttercream and ganache have time to soften.

Frequently Asked Questions

Can I halve this s’mores cake recipe?

Yes. A half batch works well when you want a smaller cake. I’d recommend dividing it between three 6-inch pans for layers with a similar thickness to the original recipe.

Keep a close eye on the cakes as they bake because smaller layers may finish sooner.

Do I need a kitchen torch?

For the full toasted marshmallow flavor, yes, I strongly recommend using one.

The torch caramelizes the surface of the meringue and creates those little toasted bits that are mixed throughout the filling and frosting. Without torching, the meringue will still be sweet and fluffy, but it won’t have the same roasted marshmallow flavor.

Can I use dark chocolate instead of milk chocolate in the ganache filling?

Yes, but you need to adjust the ganache ratio. For a dark chocolate ganache made with 60 to 65% cocoa chocolate, use 240g dark chocolate and 1 cup of heavy cream.

Milk chocolate creates a sweeter, more classic s’mores flavor, while dark chocolate makes the cake richer and less sweet.

Why is my chocolate ganache too runny?

The most likely reason is that it’s still too warm.

Ganache thickens significantly as it cools. Let it sit at room temperature longer, or chill it briefly and stir as needed until it reaches a spreadable consistency.

Also, make sure you’re using the correct chocolate-to-cream ratio. Milk chocolate and dark chocolate require different proportions.

Can I use marshmallow fluff instead of the toasted meringue buttercream?

I don’t recommend it as a direct substitute in this recipe. The homemade meringue is mixed with butter to create the toasted meringue buttercream that’s used both between the cake layers and around the outside of the cake.

Store-bought marshmallow fluff has a different consistency and won’t create the same stable, fluffy buttercream once the butter is added.

How do I keep the cake layers from sliding?

Make sure the chocolate ganache is fully cooled and thick before assembling the cake. Don’t overfill the layers, and use cool cake layers whenever possible.

Once the cake is stacked, chill it for about 20 minutes in the freezer or 30 minutes in the fridge before frosting. This gives the fillings time to firm up and helps everything stay in place.

Can I make the toasted meringue buttercream with a hand mixer?

You can, but it will take longer and require more patience. A stand mixer is much easier for this recipe because the meringue needs to be whipped for around 10 minutes, and then the butter needs to be gradually incorporated.

If you use a hand mixer, make sure the meringue reaches true stiff, glossy peaks before adding the butter.

Tips for Making the Best S’mores Cake

• Properly measure your flour. Spoon it into your measuring cup and level it with a knife, or use a kitchen scale for the most accurate results.
• Use room-temperature ingredients. They mix together more easily and help create smoother batters, ganache, and frosting.
• Cool the meringue before adding butter. Warm meringue is one of the most common causes of soupy buttercream.
• Chill the stacked cake before frosting. With both ganache and buttercream between the layers, this extra step makes the cake much easier to finish.
• If your cake layers turn out less than perfect, check out my cake troubleshooting guide to figure out what might have happened.

Let Me Know What You Think!

If you make this s’mores cake recipe, I’d love to hear what you think! Let me know by leaving a rating and comment below.

And don’t forget to tag me @chelsweets and use #chelsweets if you share on social media so I can see your amazing creations.

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