The Ultimate Gluten-Free Peanut Butter Cup Cake (Flourless & Decadent)

If you’re a peanut butter and chocolate lover, this cake is about to become one of your absolute favorites. Our gluten-free peanut butter cup cake cake is rich, decadent, and incredibly satisfying—without any flour at all. It starts with a fudgy flourless chocolate cake base, is topped with the creamiest peanut butter frosting, finished with a silky chocolate ganache, and sprinkled with chopped peanut butter cups. Every bite is pure chocolate–peanut butter bliss.

This recipe has become a staple in our home. I’ve brought it to birthday parties, family gatherings, and celebrations, and it’s the dessert people ask me to make again and again. In fact, my daughter recently requested it, which reminded me that it’s finally time to share this perfected recipe.

If you’re looking for a show-stopping gluten-free dessert that everyone—gluten-free or not—will rave about, this is it.

Perfect for Birthdays and Celebrations

This cake has become one of those recipes that friends and family immediately associate with celebrations. It’s rich, crowd-pleasing, and surprisingly simple to make.

The combination of fudgy chocolate cake, creamy peanut butter frosting, silky ganache, and peanut butter cups creates the ultimate dessert experience.

If you bring this to a party, don’t be surprised if people ask you for the recipe before the night is over. Whether it’s for a birthday, holiday, or just a weekend treat, this is THEE dessert that people remember.

And in our house, it’s officially earned its place as a family favorite.

Why You’ll Love This Gluten-Free Peanut Butter Cupcake Cake

There’s something magical about the combination of chocolate and peanut butter. The deep richness of the chocolate pairs perfectly with the creamy, slightly salty peanut butter frosting. What makes this recipe even better is that the cake base is naturally gluten-free, thanks to its flourless chocolate foundation.

Here’s why this cake is such a hit:

• Naturally gluten-free with a flourless chocolate cake base
• Incredibly rich and fudgy texture
• Creamy peanut butter frosting that balances the chocolate perfectly
• Chocolate ganache topping for extra decadence
• Chopped peanut butter cups add texture and flavor
• Perfect for birthdays, celebrations, and parties

Tips for the Best Gluten-Free Peanut Butter Cupcake Cake

This cake is baked in an 8-inch round cake pan, which helps create that rich, thick, bakery-style cake layer. I love this parchment liners that are precut to line my pan. Because this recipe is flourless, the smaller pan gives the cake the perfect dense, fudgy texture instead of spreading too thin.

Another ingredient that makes a big difference in the flavor is Dutch-process cocoa powder. Dutch-process cocoa is cocoa that has been treated with an alkalizing process to neutralize its natural acidity. This gives it a darker color, smoother flavor, and deeper chocolate taste compared to regular natural cocoa powder. While natural cocoa powder can work in this recipe, Dutch-process cocoa creates that extra rich, almost brownie-like chocolate flavor that pairs perfectly with the peanut butter frosting and chocolate ganache.

Use good-quality chocolate. Since the cake is flourless, the chocolate flavor really shines through. Don’t overbake. The cake should remain slightly fudgy in the center. Let everything cool before frosting. This keeps the frosting fluffy and prevents melting. Chill slightly before serving. This helps the ganache set and makes slicing easier.

Frequently Asked Questions

Can I use natural cocoa powder instead of Dutch-process cocoa?

Yes, natural cocoa powder will work if that’s what you have on hand. However, Dutch-process cocoa powder gives this cake a deeper chocolate flavor and darker color. Because Dutch-process cocoa has been alkalized to remove acidity, it creates a smoother and more rich chocolate taste, which works beautifully in this flourless cake.

Is this cake completely gluten-free?

Yes! This cake is naturally gluten-free because it does not use any flour. Just be sure the chocolate chips, cocoa powder, and peanut butter cups you use are labeled gluten-free to avoid cross-contamination.

What size pan should I use?

This recipe is designed for an 8-inch round cake pan. I love the precut unbleached parchment liners. Using a smaller pan helps the cake bake up thick and fudgy instead of thin. If you use a 9-inch pan, the cake will bake faster and may not be as tall.

Can I make this cake ahead of time?

Absolutely. This cake actually tastes even better after it has had time to set. You can make it a day in advance and store it in the refrigerator until ready to serve.

How should I store leftover cake?

Store leftover cake covered in the refrigerator for up to 4 days. Because of the ganache and frosting, keeping it chilled helps maintain the best texture.

Can I freeze this cake?

Yes! You can freeze the cake for up to 2 months. Wrap slices tightly in plastic wrap and place in an airtight container. Let it thaw in the refrigerator before serving.

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The Ultimate Gluten-Free Peanut Butter Cup Cake Cake (Flourless & Decadent)

Ingredients

For the cake:

• 1 cup semisweet chocolate chips or chopped chocolate
• 1/2 cup butter (1 stick)
• 3/4 cup granulated sugar
• 1/4 teaspoon salt
• 1 teaspoon vanilla extract
• 3 eggs slightly beaten
• 1/2 cup Dutch process cocoa or unsweetened cocoa

For the peanut butter frosting:

• 3 tablespoons butter at room temperature
• ½ cup creamy peanut butter (I use all natural)
• 3/4 cup powdered sugar
• 1 tablespoon heavy cream
• 1/2 teaspoon vanilla extract
• Pinch of salt

For the chocolate ganache:

• 1/2 cup semisweet chocolate chips or chopped chocolate
• 1/4 cup heavy cream

For the garnish:

• 10-20 peanut butter cups chopped

Instructions

• Preheat oven to 375 degrees F. Grease an 8-inch round cake pan with nonstick cooking spray. Cut a piece of parchment to fit the bottom of the pan. Place it in the bottom of the pan and spray it with nonstick cooking spray. Set aside.
• To make the cake, put the chocolate and butter in a large microwave-safe bowl, and heat until the butter is melted and the chips are soft, about one minute. Stir until the chocolate is melted and the mixture is smooth. If you need to reheat, do for 10 seconds at a time and stir. Add the sugar, salt, and vanilla extract and stir to combine.
• Add the eggs and stir until smooth. Add the cocoa powder and stir until just combined. Don’t over mix.
• Pour the batter into the prepared pan and bake the cake for 25 minutes or until the cake has a thin crust on the top.
• Let the cake cool on a wire cooling rack for 10 minutes. Loosen the edges of the pan with a butter knife and carefully turn it upside down onto a cake plate or serving plate. The bottom of the cake will now be the top of the cake. Let the cake cool completely.
• While the cake is cooling make the peanut butter frosting. With a handheld mixer or stand mixer, beat the butter on medium speed for about 1 minute. Add the peanut butter, powdered sugar, heavy cream, vanilla extract, and salt. Beat on low speed until combined and then increase to high speed and beat until smooth and creamy, about 3 minutes. If the frosting is too thin, add a little more powdered sugar. If the frosting is too thick, add a little more cream.
• Next, make the chocolate ganache. Combine the chocolate and cream in a small microwave-safe bowl. Place in the microwave and heat for 30 seconds. Remove and stir. If the chocolate isn’t melted, place back in the microwave for 15 seconds. Remove and stir again, until smooth. If there are a few unmelted chocolate chips, that is fine, keep stirring until they melt into the mixture. If you need to put the ganache back in the microwave, try 10 seconds.
• To assemble the cake, frost the top of the cake with the peanut butter frosting, leaving a little bit of the cake edge showing and make a little lip with the frosting. (Don’t frost the sides.) Pour and spread the chocolate ganache evenly over the peanut butter frosting. I leave a little edge so you can see the peanut butter frosting. Garnish with chopped up peanut butter cups. Let the glaze set up for a few hours before cutting and serving the cake. You can put the cake in the refrigerator to speed up the process. We also storing it in the fridge and enjoying it cold.
• Cut the cake into slices and serve.

If you’re looking for a decadent gluten-free dessert that feels extra special, this peanut butter cup cake is a must-try. It’s the perfect balance of chocolate and peanut butter, and the flourless base makes it naturally gluten-free without sacrificing flavor or texture. Whether it’s for a birthday, holiday, or just a weekend treat, this is the kind of dessert that people remember.

And in our house, it’s officially earned its place as a family favorite.

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XO,

Carly