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This Chocolate Peanut Butter Cake is one of those easy desserts that feels incredibly indulgent. Made with a chocolate cake mix and topped with a rich peanut butter frosting, it combines two classic flavors in the most delicious way.
It starts with a chocolate cake mix, making it quick and easy to get from your pantry to the oven. The real magic comes in the frosting—an easy, cooked peanut butter glaze that’s creamy, sweet, and perfect paired with chocolate.
Table of Contents
I perfected this cake when my daughter was seven. She was set on having a chocolate and peanut butter cake that reminded her of a peanut butter cup for her birthday. After a few test runs, we landed on this version—the chocolate is rich but not overpowering, and the peanut butter frosting is full of flavor. It was an instant hit in our house.
Since then, this peanut butter and chocolate combination {along with this Nutter Butter Brownie recipe and these Chocolate Peanut Butter Chip Chip Cookies} has become her cake of choice for every celebration. Whether for birthdays, special occasions, or just a weekend treat, it’s a sweet memory baked into every slice.
After more than 35 years of baking professionally and teaching others how to bake, I’ve learned that cake mix isn’t a shortcut… it’s simply one of the best tools for creating consistently delicious desserts at home.
Ingredients Need for this Recipe
- Chocolate Cake Mix: Look for a Chocolate Fudge Cake mix for the perfect texture. You can use whatever brand you prefer! Chocolate cake mix recipes are my favorite.
- Milk: I use 1% milk, but whole milk will make your cake even more rich.
- Sour Cream: This is the secret ingredient that makes this peanut butter and chocolate cake so incredibly addictive! It adds moisture and a slight tang. Greek yogurt works as a substitute in a pinch.
- Butter: Use real butter, not margarine, for the best flavor and texture. Let it come to room temperature before starting.
- Peanut Butter: Be sure to use creamy peanut butter, and avoid the natural peanut butters that can make the frosting too oily.
See recipe card for full information on ingredients and quantities.
How to make a Chocolate and Peanut Butter Cake
Step 1: Making Cake Batter
Preheat your oven to 350° and spray a 9×13 baking pan with nonstick spray. Combine chocolate cake mix, milk, vegetable oil, sour cream, and eggs in a medium bowl. Mix with an electric mixer until well combined and smooth.
Step 2: Adding Batter to Pan
Pour batter into the prepared pan and spread into an even layer.
Step 3: Baking the Cake
Bake for 25-35 minutes or until a toothpick inserted in the center comes out with just a few crumbs. Cool completely in the pan.
Step 4: Making Cooked Frosting
Once the cake is almost completely cooled, combine butter, peanut butter, and milk in a small saucepan over medium heat. Whisk until melted and smooth, but not boiling. Remove from heat and whisk in powdered sugar until completely smooth. Stir in vanilla bean paste.
Step 5: Adding Frosting to Cake
Pour frosting over the cooled chocolate peanut butter cake immediately. Spread out into an even layer.
Step 6: Finishing Cake
Top with your favorite chocolate and peanut butter candies and cookies. Let the frosting set completely before cutting and serving.
Expert Tips
- Let the cake cool completely before frosting. I know it’s tempting to frost a warm cake, but patience pays off here. Hot cake will melt your beautiful peanut butter frosting and create a mess instead of that perfect glossy finish.
- Make the frosting while the cake is cooling. The peanut butter frosting should be poured on warm so it spreads easily and creates that smooth, professional look. Time it so you’re finishing the frosting just as the cake finishes cooling. Just like on this Peanut Butter Bundt Cake.
- Use name-brand peanut butter for best results. Natural peanut butters can make the frosting separate and become oily. Stick with creamy varieties like Jif or Skippy for consistent, smooth frosting every time.
- Get creative with toppings. While it’s delicious as-is, try sprinkling chopped peanuts, mini chocolate chips, or even crushed peanut butter cups on top of the warm frosting for a little something extra.
Storage and Freezing
Store: Keep leftover chocolate peanut butter sheet cake covered tightly with plastic wrap or in an airtight container in the refrigerator for up to 4 days.
Freeze: To freeze, wrap the whole cake tightly in plastic wrap, then aluminum foil. It will keep in the freezer for up to 3 months. Thaw overnight in the refrigerator before serving. The frosting may lose some of its glossy finish but will still taste amazing.
Recipe FAQs
I don’t recommend it for the frosting – the chunks can make it difficult to get that smooth, pourable consistency we’re after. If you love that crunch, stick with creamy peanut butter for the frosting and sprinkle chopped peanuts on top instead!
Absolutely! While the cake mix makes this super easy, you can definitely use your favorite homemade chocolate cake recipe. Just bake it in a 9×13 pan and follow the same frosting instructions. The peanut butter frosting goes great with any chocolate cake.
Do you love chocolate cake? Try these recipes..
Did you try this recipe? Leave a ⭐️⭐️⭐️⭐️⭐️ review below and tag @practicallyhomemade on Pinterest!
Easy Chocolate Peanut Butter Cake Recipe
Ingredients
Chocolate Cake
- 1 box chocolate fudge cake mix, {13.25 ounces}
- 1 cup milk, {I used 1%}
- ½ cup vegetable oil
- ¼ cup sour cream
- 3 large eggs
Peanut Butter Frosting
- ½ cup butter
- ⅔ cup creamy peanut butter
- 6 Tablespoons milk, {I used 1%}
- 2 ½ cup powdered sugar
- 1 teaspoon vanilla bean paste, {or vanilla extract}
Instructions
- Preheat the oven to 350°.
Chocolate Cake
- To prepare the cake batter: Combine cake mix, milk, vegetable oil, sour cream and eggs to medium bowl and stir with an electric mixer until well combined. Spray a 9×13 baking pan with nonstick spray and pour prepared batter into the greased pan. Spread into an even layer.
- Bake in a preheated oven for 25-35 minutes or until a toothpick inserted in the center comes out with only a few crumbs. Cool completely in the pan.
Peanut Butter Frosting
- Once the cake is almost completely cooled, combine the first 3 frosting ingredients in a small saucepan over medium heat. Whisk until the mixture has melted but not boiling. Remove from heat, add powdered sugar and whisk until smooth. Add vanilla extract and stir until completely incorporated. Pour frosting over the cooled cake.
- Let the frosting set and serve. Keep covered with plastic wrap and refrigerated for up to 4 days.
Notes
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
The perfect flavor combination.