Chocolate Peanut Butter Cake

Ingredient Notes & Substitutions

See recipe card at the bottom of this post for full ingredient list and measurements.

Chocolate Cake Ingredients

Cocoa Powder - I really like using Dutch processed cocoa powder in this cake for a dark chocolate flavor, but you can use natural unsweetened cocoa powder if you prefer for a more classic chocolate cake flavor.

Whole Milk - I recommend whole milk for its richness, though you can substitute a lowfat milk if you prefer.

Vegetable Oil - Vegetable oil adds needed moisture and fat to the cake batter, and it creates a cake that's more tender than if we used butter instead.

Sour Cream - Sour cream helps to create a moist cake. Because of its acidity, it's also responsible for activating the baking soda, which helps the cake to rise when baking. You can substitute Greek yogurt for the sour cream, but note that doing so may add a subtle tangy flavor to the cake.

Hot Coffee - The hot liquid blooms the cocoa powder, deepening its chocolate flavor, while the coffee enhances the flavor of the chocolate. I promise the cake doesn't taste like coffee (I'm not a coffee drinker, so I won't lie to you!), but you can substitute an equal measure of boiling water if you don't want to use coffee.

Peanut Butter Cream Cheese Frosting & Toppings Ingredients

Peanut Butter - This recipe was designed using a creamy, conventional peanut butter (I used Jif brand). Avoid natural or crunchy peanut butters, which don't have the right texture for this recipe. We'll also melt some peanut butter to drizzle over the cake.

Cream Cheese - For the best flavor and texture, use a full-fat cream cheese block. Do not use low fat cream cheese or cream cheese from a tub.

Chocolate Chips - I'm breaking my own rule here and using chocolate chips (combined with heavy cream) to make chocolate ganache for drizzling over the cake. I preach using bakers chocolate for ganache since that doesn't include stabilizers, but since we're using such a small amount of chocolate here I decided it's not worth it to splurge on the good stuff.

Peanut Butter Cups - I used a combination of Reese's Miniature Cups (which I cut into halves of quarters) and Reese's minis (the tiny unwrapped ones) to top the cake. You can use any variety you like, and I include other toppings ideas below.

More Topping Ideas

Feel free to get creative with the toppings! You can use some or all of the toppings I suggest in the recipe, or try some of these other ideas:

• Other chocolate peanut butter candies (like Reese's Pieces)
• Chopped peanuts
• Peanut butter chips
• Chocolate chips
• Chocolate shavings or curls
• Chocolate jimmies

Special Equipment

In addition to essential baking equipment (like a mixing bowl and spatula), I recommend some special tools for making this recipe.

• A 9x13 metal baking pan, for baking the cake.
• A stand mixer with the paddle attachment or an electric hand mixer, for mixing the frosting.
• An offset spatula, for spreading the frosting.

Step-By-Step Recipe Instructions

See recipe card at the bottom of this post for detailed recipe instructions.

Step 1: Make the cake batter. Whisk together flour, sugar, cocoa powder, baking powder, baking soda, and salt. Add milk, oil, sour cream, eggs, and vanilla. Stir until well combined.

Step 2: Add hot coffee to the batter, carefully mixing with a whisk until well blended. The batter will now be very thin.

Recipe Tips

When the dry and wet ingredients in the cake batter are mixed together, the batter will be thick and look a lot like brownie batter. When you add the hot coffee, it will at first seem like it won't blend into the batter, but keep mixing. It will eventually come together and the batter will be thin and pourable.

Before making the frosting, be sure to let the cream cheese and butter come to a cool room temperature to ensure a smooth frosting. If you're in a hurry, check out my tips for bringing ingredients to room temperature more quickly.

For drizzling the chocolate ganache and melted peanut butter, my perfectionist side got the best of me and I used a piping bag. But you can absolutely drizzle these toppings onto the cake using a spoon or a cup with a pour spout!

Storage Instructions

Refrigerator: Once frosted, the cake will need to be refrigerated and can be stored in the fridge in a sealed container for up to 4 days.

Freezing: Before it's frosted, the cake can be baked ahead of time and frozen. Wrap the completely cooled cake in plastic wrap followed by a layer of foil before freezing for up to 3 months. Defrost the cake at room temperature before frosting and serving.