Mouthwatering S’mores Loaf Cake

Here is my favorite s’mores loaf cake recipe, with a soft chocolate cake base, gooey marshmallow swirls, and a crunchy graham cracker topping that brings all those campfire flavors indoors.

This s’mores loaf cake is what I make when my kids are craving something sweet but it’s too rainy for an actual campfire. I love how it captures all the messy fun of s’mores in a neat slice you can enjoy with your morning coffee.

What Kind of Cocoa Powder Should I Use?

For this s’mores loaf cake, you’ll want to stick with unsweetened dark cocoa powder as called for in the recipe. Dutch-processed cocoa powder works great here since it has a deeper, richer chocolate flavor that pairs perfectly with the graham crackers and marshmallow topping. Natural cocoa powder will also work, but it tends to be a bit more acidic and lighter in color. If you only have regular unsweetened cocoa powder on hand, that’s totally fine too – your cake will still taste amazing. Just make sure whatever cocoa you use is fresh and hasn’t been sitting in your pantry for years, as old cocoa can taste flat and won’t give you that rich chocolate flavor you’re after.

Options for Substitutions

This s’mores loaf cake is pretty forgiving when it comes to swaps, so here are some easy substitutions:

• Sour cream or Greek yogurt: If you don’t have either on hand, you can use regular plain yogurt, buttermilk, or even mayonnaise (trust me on this one!). Each will give you that tender, moist texture you’re looking for.
• Espresso or coffee: No coffee? No worries! You can replace it with the same amount of hot water mixed with 1 teaspoon of vanilla extract, or just use an extra 1/4 cup of milk.
• Unsweetened dark cocoa powder: Regular unsweetened cocoa powder works just fine here. If you only have sweetened cocoa, reduce the sugar by 2 tablespoons to balance things out.
• Graham crackers: You can crush up digestive biscuits, vanilla wafers, or even cinnamon graham crackers for a little extra flavor. Just make sure to break them into similar-sized pieces.
• Whole milk: Any milk you have works – 2%, skim, or even non-dairy alternatives like almond or oat milk. The cake might be slightly less rich with lower-fat options, but it’ll still taste great.
• Semisweet chocolate chips: Feel free to use milk chocolate chips, dark chocolate chips, or even chop up a chocolate bar. Just make sure to melt it completely before adding to the batter.

Watch Out for These Mistakes While Baking

The biggest mistake when making s’mores loaf cake is overmixing the batter once you add the flour, which can lead to a dense, tough cake instead of the tender crumb you’re after – mix just until the ingredients are combined.

Another common error is not letting your melted chocolate cool slightly before adding it to the butter mixture, as hot chocolate can cause the butter to melt and throw off your cake’s texture.

When making the marshmallow topping, make sure your egg whites are at room temperature and your bowl is completely clean and dry, since even a tiny bit of grease or yolk can prevent the whites from whipping properly.

Finally, don’t skip testing for doneness with a toothpick inserted into the center – the cake should have a few moist crumbs clinging to it, but shouldn’t be wet or gooey in the middle.

What to Serve With S’mores Loaf Cake?

This s’mores loaf cake is pretty much perfect on its own, but a scoop of vanilla ice cream alongside each slice makes it feel extra special. I love serving it with a hot cup of coffee or a cold glass of milk – the rich chocolate and graham cracker flavors pair beautifully with both. If you want to go all out, try warming up individual slices for about 10 seconds in the microwave before serving, which makes the chocolate even more gooey and brings out all those campfire vibes. Fresh berries like strawberries or raspberries also make a nice addition if you want something a little tart to balance out the sweetness.

Storage Instructions

Keep Fresh: This s’mores loaf cake stays moist and delicious when wrapped tightly in plastic wrap or stored in an airtight container at room temperature for up to 3 days. The graham cracker topping might soften a bit over time, but it still tastes amazing. If you want to keep it longer, pop it in the fridge for up to a week.

Freeze: You can absolutely freeze this cake for later! Wrap individual slices in plastic wrap and then place them in a freezer bag, or freeze the whole loaf wrapped well for up to 3 months. It’s such a treat to have a slice of s’mores cake ready to go whenever you need a chocolate fix.

Serve: Let frozen slices thaw at room temperature for about 30 minutes before enjoying. If you want to warm it up a bit, just pop a slice in the microwave for 10-15 seconds to get that fresh-baked feel again. The chocolate gets slightly melty and it’s like having s’mores all over again!

Preparation Time	20-30 minutes
Cooking Time	35-40 minutes
Total Time	55-70 minutes
Level of Difficulty	Medium

Estimated Nutrition

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

• Calories: 2200-2400
• Protein: 25-30 g
• Fat: 100-110 g
• Carbohydrates: 300-320 g

Ingredients

For the chocolate cake batter:

• 8 tbsp unsalted butter, softened
• 1 cup granulated sugar
• 1/3 cup semisweet chocolate chips, melted
• 2 eggs
• 1/4 cup sour cream or plain greek yogurt
• 1 3/4 tsp baking powder
• 1/2 tsp kosher salt
• 1/3 cup dark unsweetened cocoa powder
• 1 cup plus 1 tbsp all-purpose flour
• 1/4 cup whole milk
• 1 shot espresso or 1/4 cup brewed coffee
• 1 tsp vanilla extract

For the graham cracker layer:

• 5 graham crackers, broken in half

For the meringue topping:

• 2 egg whites, at room temperature
• 1/2 cup granulated sugar

Step 1: Prepare the Pan and Oven

Preheat your oven to 350°F (175°C).

Grease a standard loaf pan and line it with parchment paper, ensuring an overhang for easy removal of the cake later.

This step ensures your cake won’t stick and will come out smoothly.

Step 2: Mix the Wet Ingredients

• 8 tbsp unsalted butter, softened
• 1 cup granulated sugar
• 1/3 cup semisweet chocolate chips, melted
• 2 eggs
• 1/4 cup sour cream or plain Greek yogurt

In a stand mixer bowl or a large bowl with a hand mixer, cream together the softened unsalted butter and granulated sugar until the mixture is light and fluffy.

Mix in the melted semisweet chocolate chips until fully combined.

Add the eggs one at a time, mixing well after each addition, followed by the sour cream or Greek yogurt.

This process provides the base structure and richness for the cake.

Step 3: Combine Dry and Liquid Ingredients

• 1 3/4 tsp baking powder
• 1/2 tsp kosher salt
• 1/3 cup dark unsweetened cocoa powder
• 1 cup plus 1 tbsp all-purpose flour
• 1/4 cup whole milk
• 1 shot espresso or 1/4 cup brewed coffee
• 1 tsp vanilla extract

In a medium bowl, whisk together the baking powder, kosher salt, dark unsweetened cocoa powder, and all-purpose flour.

In a separate small bowl or measuring jug, whisk together the whole milk, espresso or brewed coffee, and vanilla extract.

Alternately add one-third of the dry mixture to the wet mixture, then half the milk mixture, mixing just to combine after each addition.

Repeat, ending with the last third of the dry mixture.

Mix until the batter is smooth.

I like to end with the dry ingredients for a more tender crumb.

Step 4: Layer the Batter and Graham Crackers

• batter from Step 3
• 5 graham crackers, broken in half

Pour one-third of the chocolate batter into the bottom of the prepared pan.

Lay 3 graham cracker halves over the batter.

Repeat the layering two more times: spread another third of the batter, then another layer of graham cracker halves, and finally the remaining batter, smoothing the top.

These graham cracker layers add a wonderful texture surprise in each slice!

Step 5: Bake the Cake

• assembled cake batter with graham crackers from Step 4

Bake the layered cake in the preheated oven for 35-40 minutes, or until a toothpick inserted into the center comes out with just a few moist crumbs.

Remove from the oven and let it cool slightly in the pan.

I like to let the cake cool in the pan for about 10 minutes before releasing it so it sets nicely.

Step 6: Make the Swiss Meringue

• 2 egg whites, at room temperature
• 1/2 cup granulated sugar

While the cake bakes, place the egg whites and granulated sugar in the bowl of a stand mixer.

Set the bowl over a double boiler and whisk constantly until the sugar dissolves and the mixture feels smooth between your fingers.

Remove the bowl from the heat and whip the mixture on high speed until stiff, glossy peaks form.

This makes a pillowy topping for your cake.

Step 7: Finish and Decorate

• baked cake from Step 5
• Swiss meringue from Step 6

Once slightly cooled, release the cake from the loaf pan by loosening the sides.

Spread the Swiss meringue evenly over the top of the cake with an offset spatula.

Toast the meringue with a kitchen torch until it achieves a golden brown color.

Slice and serve for the perfect show-stopping finish!

For extra flair, I sometimes sprinkle a bit of cocoa powder or chocolate shavings on top before serving.