This fluffy and moist peanut butter sheet cake is easy and quick to make. Once baked, top the peanut butter cake with homemade chocolate frosting and serve! A simple cake full of peanut butter flavor that’s ready within 30 minutes.

Easy Peanut Butter Sheet Cake recipe
It’s slightly embarrassing how much I’ve been making peanut butter sheet cake. However, once I’m shoving warm, gooey cake in my face, any self-dignity is gone anyway.
It doesn’t help how damn easy it is to make and all the ingredients are kitchen staples!
If you are one of those poor souls who thinks they can’t make homemade cake, please erase that ridiculous thought and make this cake recipe ASAP.
Old fashioned peanut cake mixes together in minutes without using any fancy equipment or techniques. You don’t even have to remember to wait for the cake to cool before slathering it with 5 minute chocolate frosting.
Better yet, this recipe can easily be transformed into one of my favorite gluten-free cake recipes. See the ingredient notes below for the suggested modifications.
Ingredient notes
This is the perfect emergency dessert for company or birthday cakes because all the ingredients are commonly stocked and ready to go!
- Flour – For a gluten-free peanut butter sheet cake, I recommend using Cup4Cup gluten-free flour, which was my preferred brand to use in my gluten-free cookbook.
- Peanut Butter – Use creamy or crunchy peanut butter, such as Skippy or Jif brands. I don’t recommend natural peanut butter in this recipe.
- Milk – Use any percentage of milk, skim, buttermilk, to whole. Alternatively, non-dairy milk may be used for a dairy-free recipe.
- Sour Cream – The addition of sour cream in the chocolate frosting adds a creamy tanginess. It may also be replaced with yogurt.
How to Make Peanut Butter sheet Cake
(Below shows step-by-step photos and modified instructions. For the complete recipe, along with ingredient amounts, scroll down to the recipe card.)
- Bring butter, peanut butter, and water to a boil.
- Remove from heat and stir the sugar into the peanut butter mixture.
- To the batter add the flour, baking soda, and salt to saucepan. Stir in the flour mixture.
- In a separate bowl whisk together milk, eggs, and vanilla. Stir into saucepan. Spread in the greased sheet pan and bake.
Warm Chocolate Frosting
Similar to a peanut butter Texas sheet cake, the chocolate frosting mixes together in a saucepan and is poured on warm cake. Chocolate goodness soaks into the cake to make ooey gooey chocolate peanut butter cake heaven.
If you want the ultimate peanut butter dessert, swap out the chocolate frosting for this gooey peanut butter glaze! Sprinkle with chopped nuts or chocolate chips.
Make Peanut Butter Cake With a Cake Mix
Looking for something a little quicker? Follow these simple directions to make peanut butter sheet cake using a cake mix.
- Preheat oven to 350. Spray 13X9″ pan with cooking spray.
- In a large bowl mix together yellow cake mix, 1 1/3 cups water, 1/3 cup peanut butter, 1/3 cup vegetable oil, 3 eggs, and 1 teaspoon vanilla using an electric mixer for 2 minutes.
- Spread in prepared pan and bake for 20-25 minutes or until inserted toothpick comes out clean.
- As soon as cake comes out of the oven make easy chocolate frosting included in recipe below OR cool completely and spread with chocolate buttercream frosting.
substituting a 9X13 baking pan
This cake recipe resembles a Texas sheet cake, but it can also be baked in a 9X13 pan. Since the cake will be thicker, it will take 35-40 minutes to bake.
suggested Toppings
I love adding chopped peanuts because of the saltiness it adds, but here are some other delicious ideas!
- Sprinkles
- Chopped Reese’s Peanut Butter Cups
- M&Ms
- Reese’s Pieces
- Flaky Sea Salt, such as Maldon
expert Tips
- Substitute chunky peanut butter in the cake.
- Using natural peanut butter is not recommended for this recipe, but if that’s all you have on hand make sure the oil is incorporated well before measuring out.
- As soon as the peanut butter cake comes out of the oven, make the easy stovetop chocolate frosting. It’s best spread on a still warm cake.
- This cake recipe can also be baked in a 9X13 pan, although I prefer a thinner cake to frosting ratio. It will take 35-40 minutes to bake in 9X13 pan.
- Yogurt can be substituted for the sour cream in the frosting.
Click here to see the
step-by-step web story instructions for this recipe!
More Peanut Butter Recipes You’ll Love!
- Tiger Butter – melted chocolate and peanut butter swirled together with chopped peanut butter cups on top
- Zucchini Brownies – fudgy brownies, with fluffy peanut butter frosting, and a creamy chocolate glaze
- Chocolate Chip Banana Cake – fluffy peanut butter buttercream frosting, moist banana cake layers, and Nutella ganache
- Buckeye Turtle Brownies – fudgy brownies, gooey caramel, pecan turtle topping
SAVE THIS recipe for Peanut Butter sheet Cake TO YOUR PINTEREST BOARD!
Let’s be friends on Pinterest! I’m always sharing great recipes!
Easy Peanut Butter Sheet Cake & Chocolate Frosting
Ingredients
Peanut Butter Cake:
- ½ cup (1 stick) unsalted butter
- 1 cup water
- ½ cup peanut butter
- 2 cups sugar
- 2 cups all-purpose flour (for gluten free I recommend Cup4Cup gluten free flour)
- ½ teaspoon baking soda
- ½ teaspoon salt
- 2 eggs
- ½ cup milk
- 1 teaspoon vanilla extract
Chocolate Frosting:
- 1/2 cup (1 stick) unsalted butter
- 6 tablespoons unsweetened cocoa powder
- 6 tablespoons sour cream
- 1 teaspoon vanilla extract
- 3 ½ cups powdered sugar
- ¼ cup chopped peanuts, for topping
Instructions
Peanut Butter Cake:
- Preheat oven to 350ºF. Grease a 10X15″ jelly roll pan. (For 9X13″ pan see recipe notes)
- In a large saucepan melt butter over medium heat. Add water and peanut butter and bring to a boil. Remove from heat and stir in sugar. To the saucepan add flour, baking soda, and salt. Stir until well blended.
- In a small bowl whisk together eggs, milk, and vanilla extract. Add liquids to saucepan and stir until very well combined and smooth. Pour into prepared pan and bake 23-25 minutes, rotating pan once during baking. Cake is done when a toothpick inserted in middle comes clean. (For 9X13″ pan see recipe notes). As soon as cake comes out of oven, make chocolate frosting.
Chocolate Frosting:
- In a medium saucepan add butter and cocoa powder. Stir together over medium heat until butter melts and mixture is very smooth.
- Remove from heat and stir in sour cream and vanilla extract. Gradually stir in powdered sugar until frosting is smooth and no lumps remain. Immediately pour on warm cake and spread evenly. Sprinkle on chopped peanuts. Eat warm to experience cake heaven.
- DID YOU MAKE THIS RECIPE?? DON'T FORGET TO LEAVE FEEDBACK AND/OR CLICK A STAR RATING ON THE RECIPE CARD
Recipe Notes
Expert Tips
- This cake recipe can also be baked in a 9X13 pan, although I prefer the thinner cake to frosting ratio. It will take 35-40 minutes to bake in 9X13 pan.
- Substitute chunky peanut butter in the cake.
- Using natural peanut butter is not recommended for this recipe, but if that’s all you have on hand make sure the oil is incorporated well before measuring out.
- As soon as the peanut butter cake comes out of the oven, make the easy stovetop chocolate frosting. It’s best spread on a still warm cake.
- Yogurt can be substituted for the sour cream in the frosting
Peanut Butter Cake recipe adapted from All Recipes and chocolate frosting from The Food Charlatan
Nutrition
This post contains affiliate links. My opinions are always my own. If you purchase a product through an affiliate link, I make a small commission – at no cost to you. Read full Privacy Policy here.
Tracy Gardner says
Has anyone tried to divide this recipe in half? I dont need an entire sheet pan… more like half.
Melissa says
Hi Tracy,
You can use the slider bar on the recipe card to downsize the recipe however you like. For a half recipe, you can bake it in a 8X8 inch pan. The cake will probably be slightly thicker, though, so it will have to be baked a few minutes longer. Enjoy!
Best,
Melissa
Cindy says
This cake is delicious. I froze some in individual packets. Take it out microwave, Yum.
Melissa says
Hey Cindy,
You inspired me to make this cake today with “warm out of the microwave.” That sounds like heaven on Earth! Thank you for writing!
Best,
Melissa
Dana says
I understand the obsession. This cake is so good that after trying it, I had to take the rest in to work because I was afraid I might eat the whole thing.
Melissa says
I hear ya, sista. I had to practice some serious restraint around this dessert.
Roslia santamaria says
This looks super tasty!! I can’t wait to give it a try! It’s all delicious ingredients 🙂
Melissa says
Oh my goodness, I’m obsessed with this cake. It goes fast, so be forewarned!