You don't have to make a three layer cake to enjoy one of the best chocolate and peanut butter cakes! My shortcut version of my mom's Chocolate Peanut Butter Cake starts with a cake mix and bakes in a 9x13 pan.
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It tastes like a moist cake-like brownie with a peanut butter filling and a thick layer of pourable homemade chocolate frosting on top.
I developed this shortcut version from the "from-scratch" cake my mom always made while I was growing up. I wanted to make it a little easier with a cake mix but result in the same rich, dense texture.
I tested this peanut butter & chocolate cake over and over until I had the ingredients and baking time just right for you!
It’s my favorite cake! I once baked it in college in my dorm’s community kitchen and nearly ate the whole thing myself in just a few days. True story.
If you're like me and LOVE the combo of chocolate and peanut butter together, try my Instant Pot Chocolate Peanut Butter Swirl Cheesecake, Chocolate Peanut Butter Rice Crispy Bars or No Bake Peanut Butter Energy Bites after this recipe.
I have made it for my own family for Thanksgiving and Christmas alongside my favorite pies, Cast Iron Skillet Pecan Pie, Shortcut Chocolate Cherry Pie (Galette), and 2 Ingredient Pumpkin Pie Minis. It's also a big hit at church potlucks!
I hope you will agree that it is the best chocolate peanut butter cake! Bonus that it starts with a cake mix and it's a tall sheet cake pan baked in a 9x13 pan.
Shortcuts
- Start with a boxed cake mix – Make this chocolate peanut butter cake with cake mix. It uses a Devil’s Food cake mix with a few tweaks. Adding butter, coffee, sugar, and eggs gives it that mouthwatering homemade taste!
- No stovetop needed – Of course you can use the stovetop to make the frosting, if you want to, but I use the microwave. This saves time and means fewer dishes to wash.
Ingredients
Here’s everything you need to bake this chocolate peanut butter cake recipe.
Scroll down to printable recipe for exact ingredient quantities.
- Butter – If you’re baking a lot, just buy butter in bulk and freeze extra sticks. Just thaw them in the fridge overnight when you need more.
- Coffee or water – Coffee adds depth and enhances the chocolate flavor, but don’t worry, it won’t make the cake taste like coffee. Even kids can’t tell! Water also works fine.
- Devil’s Food cake mix – Duncan Hines is my go-to, but any brand of Devil’s Food will work.
- Sugar – Granulated sugar is all you need here. Adding it to the cake mix helps with the rich, dense texture I was going for.
- Creamy peanut butter – Just this one ingredient makes up the peanut butter layer. It balances out the sweet cake and extra sweet chocolate icing.
- Milk – Measure milk carefully! Too much can make the frosting thin, while too little can make it stiff and hard to spread. Start with the recipe amount, then adjust if needed.
- Vanilla extract – A teaspoon is already plenty, but if you love vanilla, you can add a little extra for a stronger flavor.
- Powdered sugar – Sift powdered sugar before mixing to avoid lumps. I like to measure powdered sugar and cocoa right into a large metal sieve or strainer set over a bowl, then shake them through together. This removes any tiny lumps and blends the two ingredients evenly.
- Unsweetened cocoa powder – Always use unsweetened cocoa powder here, not hot cocoa mix, which has added sugar.
Substitutions & Variations
- Coffee or water for the cake base – Use whichever you have on hand, and the recipe will still turn out fudgy and delicious.
- Any Chocolate Cake Mix – I love the deep chocolate color of a Devils Food Cake mix, but any 15.25 ounce chocolate cake mix will work.
How to Make Chocolate Peanut Butter Cake with Cake Mix
Scroll down to the bottom for the printable recipe with detailed instructions.
- Preheat the oven to 350°F and grease a 13x9-inch baking pan.
- Melt butter with hot coffee, then whisk in the cake mix, sugar, and eggs until smooth. Bake until a toothpick comes out almost clean.
- Melt creamy peanut butter and spread it over the warm cake, then chill to help it set. Scroll down to the printable recipe for extra tips on the smoothest peanut butter layer!
If you try to add the chocolate icing before the peanut butter filling layer chills, you may get chocolate-peanut butter swirls.
Make the chocolate peanut butter cake frosting
- Melt butter with milk, stir in vanilla, then mix with powdered sugar and cocoa until glossy.
- Pour and spread the frosting over the peanut butter layer.
- Let the cake cool or chill until firm enough to cut a clean slice.
That’s it. All done! Slice, serve, and enjoy. My favorite Chocolate and Peanut Butter Cake... soon to be yours!
I hope this will become a new dessert tradition with your family, too.
Pro Tips
The chocolate icing will start to thicken as it cools, so make it right before you’re ready to pour it onto the cake. If you wait too long, it may set up in the pan before you can use it.
Using coffee instead of water enhances the chocolate flavor. No worries if you just use water or milk, though. It's still delicious.
To adjust a recipe that calls for a 15.25 ounce cake mix to use a 13.25 ounce cake mix, choose one of these options. 1. To a 13.25 ounce cake mix, add 2 tablespoons all purpose flour and 2 tablespoons sugar. 2. To a 13.25 ounce cake mix reduce amount of water or liquid by 2 tablespoons.
How to Serve Chocolate Peanut Butter Cake
Serve this rich chocolate sheet cake right from the pan at potlucks, game day, or birthdays and holidays. It's also decadent enough to serve in small pieces at special occasions like bridal showers, baby showers and birthday parties.
If you’re planning to include it in your holiday spread, serve it alongside cranberry orange cookies, maple pecan tassies, and other treats.
As for drinks, coffee punch and a cranberry sangria mocktail are both great options!
How to Store
This chocolate fudge peanut butter cake is ready to serve once the icing has firmed up enough to slice.
Want to save it for later? Cover and store it at room temperature or in the refrigerator. Either option works well to keep the frosting set and the cake moist. I think it actually gets better the second day, as the flavors meld together.
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Chocolate Peanut Butter Cake (9x13)
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Equipment
- 9x13 baking pan (or baking dish)
Ingredients
For the Cake
- 1 cup butter (2 sticks)
- 1 cup hot or cold coffee* (or water)
- 1 box Devil’s Food cake mix (15.25-ounce)(I used Duncan Hines)
- ½ cup sugar
- 2 large eggs
Peanut Butter Layer
- 2 cups creamy peanut butter (one 16-ounce jar)
Chocolate Peanut Butter Cake Frosting
- ½ cup butter
- 6 tablespoons milk* (¼ cup plus 2 tablespoons)
- 1 teaspoon vanilla extract
- 1 (16 ounce) box or package powdered sugar (3 ¾ cups)
- ¼ cup unsweetened cocoa powder
Instructions
For the Cake
- Preheat the oven to 350°F. If using a nonstick pan, coat ONLY the bottom of a 13x9-inch baking pan or dish with cooking spray or lightly grease the bottom with butter. See Pro Tip in NOTES below.
- In a large microwave-safe bowl, combine 1 cup butter and the coffee. Microwave on HIGH for 1 minute, then stir until the butter melts. (You can also melt the butter in a saucepan on the stovetop.
- Add the cake mix and sugar; whisk together for about 20 seconds. This will help cool the hot butter and coffee.
- Add the eggs, then whisk or beat with an electric mixer for about 30 seconds, or until smooth.
- Pour the batter into the prepared pan and bake for 23 to 25 minutes, or until a toothpick inserted in the center comes out almost clean. Do not overbake. The texture should be a cross between a brownie and a cake.
For the Peanut Butter Layer
- Melt the peanut butter. You can either place it in a bowl and microwave on HIGH for about 30 seconds, or heat it in a saucepan over medium-low heat, stirring often.
- Pour the melted peanut butter over the warm cake, spreading it evenly to the edges.
- Let the cake cool for 30 minutes, then refrigerate for at least 15 minutes. This allows the peanut butter layer to firm up so the chocolate frosting won’t swirl into it when poured.
Chocolate Peanut Butter Cake Frosting
- In a medium saucepan, combine the butter and milk. Cook over medium heat, stirring often, just until the butter melts. Remove from heat and stir in the vanilla.
- In a separate bowl, whisk together the powdered sugar and cocoa.
- Add the powdered sugar mixture to the butter mixture in the saucepan. Stir until completely smooth.
- Pour the chocolate frosting over the chilled peanut butter layer, carefully spreading it to the edges.
- Let cool or chill until firm enough to slice.
Notes
- Greasing ONLY the bottom of a nonstick baking pan allows the cake mix batter to "climb" up the sides of the pan, making it taller. It also prevents it from pulling away from the pan, whiling cooling, which would makes the peanut butter layer run down the sides. It's ok to lightly grease the entire pan if it's aluminum or stainless steel.
- Cut the cold stick of butter into four pieces before microwaving to melt faster and prevent it from popping "open".
- *Coffee enhances the flavor of chocolate but does not make the cake taste like coffee. Water can be used.
- *I used whole milk but any milk will work.
Nutrition
Nutrition analysis on GritsAndGouda.com recipes are mostly calculated on an online nutrition calculator. I am not a dietitian and nutritional information is an estimate and can vary based on products used.
Bonnie McGee
I will definitely try this recipe. It looks wonderful, especially for a crowd.
Kathleen
Thank you! Yes, it is perfect for a family gathering or a potluck!
Judy Dye
I love how easy it is to make. My family loves peanut butter and chocolate! Thanks
Kathleen
I'm all about making a recipe easier while keeping it yummy! So glad you love it!