Chocolate Peanut Butter Cake

Three layers of decadent chocolate cake, fluffy peanut butter buttercream, a glossy chocolate ganache drizzle, and peanut butter cups. This Chocolate Peanut Butter Cake is a true showstopper!

This Chocolate Peanut Butter Cake was the first cake recipe on Bunsen Burner Bakery. A decade later, it’s been joined by dozens more, but this cake remains one of the most popular on my site – and for good reason! It’s the chocolate cake I make most often and the base recipe used for many of my other chocolate cakes.

The crumb is soft and velvety, sturdy enough to stack, and full of deep chocolate flavor that stands up to the peanut butter frosting and a rich ganache dripping down over the sides. Think it can’t get any better? If you love a little extra texture, add chopped peanut butter cups between each layer of cake, and more to decorate the top!

This recipe was well overdue for a refresher with clearer instructions, updated tips, ingredient swap suggestions, and new photos. And while this cake has nothing in particular to do with Halloween and is delicious year-round, it somehow seemed appropriate to share it as a reminder of what you can do with that pile of leftover peanut butter cups!

Ingredients and Substitutions

Here’s what you need to make these Apple Pie Bars, along with some ingredient suggestions and substitutions.

• Flour: Use all-purpose flour, or for a gluten-free version, use a 1:1 gluten-free baking blend with xanthan gum. Let the batter rest for 10 minutes before baking for better hydration.
• Cocoa Powder: Use natural unsweetened cocoa powder for the best flavor and texture. In a pinch, you can swap with Dutch-processed cocoa powder, but add an extra 1/4 teaspoon baking power.
• Oil: Use a neutral oil, like vegetable, grapeseed, or avocado oil, which will keep the cake fluffier and more moist than melted butter.
• Eggs: To make an egg-free version of this cake, use a flax egg to replace each large egg (1 tablespoon ground flaxseed + 2 tablespoons of water, mixed and rested until gelled, per egg) and add 1 extra tablespoon of oil for tenderness.
• Buttermilk: Mix whole milk with 1 tablespoon white vinegar or lemon juice per cup and rest for 5 minutes, or use full-fat Greek yogurt thinned with milk.
• Hot Coffee: Hot coffee intensifies the chocolate flavor and helps to bloom the cocoa powder, but hot water can be used as an alternative.
• Peanut Butter: Use creamy, no-stir commercial peanut butter for the most stable frosting.
• Peanut Butter Cups: Either full-size or miniature peanut butter cups can be used.

How to Make Chocolate Peanut Butter Cup Cake

1. Make the Cake Batter: Combine the dry ingredients in a large bowl. In a separate bowl, whisk the eggs, buttermilk, coffee, oil, and vanilla extract. Stir the wet ingredients into the dry ingredients until no dry streaks remain.

2. Bake the Cakes: Divide the batter evenly into three cake pans and bake until the center springs back and a tester comes out with a few moist crumbs.

3. Make the Frosting: Beat the butter and peanut butter until pale and fluffy. Add the peanut butter, vanilla extract, and salt and mix until well combined. Slowly add the confectioners’ sugar, followed by heavy cream, whipping on high speed until soft and fluffy.
4. Make the Ganache: Heat the heavy cream, pour it over the chocolate, and stir until fully melted and glossy.
5. Assemble the Cake: Level the layers if needed. Cover the bottom layer of cake with 1 cup of frosting and half of the chopped peanut butter cups. Top with a second cake layer and cover with another cup of the frosting and the rest of the chopped peanut butter cups. Top with the final cake layer. Apply a thin crumb coat, chill, and finish with a smooth outer coat of frosting.

6. Decorate: Spoon the cooled but still fluid ganache over the top of the cake and gently nudge down the sides to create drips, then decorate with additional swirls of frosting and peanut butter cups.

Moist for Days

One of the reasons I love this chocolate cake so much is that it stays soft for days! Thanks to the addition of oil, the cake remains fluffy and moist without drying out or getting stale. What’s the magic secret? We can explain it all with my favorite subject… kitchen chemistry!

Kitchen Chemistry

At room temperature, liquid oils remain fluid while butter sets into a crystalline solid. Those solid fat crystals firm as a cake cools, whereas liquid fats stay supple, preventing the crumb from tightening as the cake cools.

A few practical notes: choose a high-quality neutral oil, such as canola, safflower, or refined sunflower oil to avoid competing flavors. Mix just until combined to preserve the delicate structure. For the longest-lasting, most tender chocolate layers, stick with oil!

Tips and Tricks for the Best Chocolate Peanut Butter Cake

1. Hot Coffee: Add the coffee while it is very hot to bloom the cocoa for maximum flavor.
2. Chill Layers: Cold cake layers are easier to level, fill, and frost cleanly.
3. Adjust Frosting Texture: If the frosting seems soft, add a few tablespoons of confectioners’ sugar. If it’s too stiff, add a teaspoon of cream at a time and rewhip.
4. Make Ahead: Bake the cake layers up to 2 days in advance or freeze for up to 2 months. Frosting can be stored in the refrigerator for up a week; rewhip before using. Assemble the entire cake the day before serving if desired.
5. Storage: Cake can be stored at room temperature for 1-2 days, refrigerated for up to 4 days, or frozen for up to 2 months. Bring cake slices up to room temperature for the best texture.
6. Recommended Tools: 8-inch Metal Cake Pans | Kitchen Scale | Stand Mixer | Offset Spatula | High-Quality Cocoa Powder

More Chocolate Peanut Butter Desserts

• Peanut Butter Stuffed Brownies
• Chocolate Peanut Butter Cup Bundt Cake
• No Bake Peanut Butter Cheesecake
• Peanut Butter Cup Cookie Cake
• Chocolate Peanut Butter Cheesecake
• Fluffernutter Brownies

This recipe was originally published in June 2014 and updated with new photographs and helpful tips in October 2025.