Peanut butter lover? You’re in the right place! This moist peanut butter sheet cake is decadent, peanut butter-forward, and super easy to make!
This thick and bouncy cake is loaded with real peanut butter for tons of flavor and made easily on a sheet pan. You can finish it with peanut butter cream cheese frosting (as pictured in this post) or even a chocolate cream cheese frosting for that choco-peanut pair!
As a busy mom who loves to bake, I want a decadent dessert that gives me all the flavor and texture I’m looking for without all the hassle. This sheet cake requires just one bowl, 9 ingredients, and about 45 minutes to make.
Plus, baking it on a sheet pan means you don’t have to worry about layering and decorating. Just spread on your frosting, slice it up, and you’re good to go!
Peanut Butter Sheet Cake Ingredients & Substitutions
Here’s everything you need:
- Neutral oil. Like canola or vegetable oil. If you like baking with coconut oil, you can use it here in liquid form, just know you will get a hint of that flavor in your cake.
- Creamy smooth peanut butter. You’ll need one that’s more processed and is not separated in the jar. I use Jif.
- Light brown sugar.
- Eggs.
- Vanilla extract.
- Milk. Any percentage dairy milk or any unsweetened, unflavored, non-dairy milk will do.
- All-purpose flour.
- Cornstarch. This gives you a fluffier cake.
- Baking powder.
Sheet Peanut Butter Cake Tips and Tricks
How to Make Peanut Butter Cake Batter
Start by creaming together your peanut butter, oil, and brown sugar with hand mixer on high until it’s well-combined. You’ll notice some bubbles in your mixture.
Then, add the eggs and mix again. It’s always best practice to crack your eggs into a separate bowl and then add them to your mixture, so you can easily spot and fish out any shells (or if you get a bloody egg, your other ingredients won’t be wasted!).
Once your eggs are integrated, add the vanilla extract and milk and use the hand mixer on low to combine. Finally, add the flour, cornstarch, and baking powder and use your hand mixer one last time to beat until smooth.
How to Bake a Cake on a Sheet Pan
Line a 9×13-inch sheet pan with a piece of parchment paper. I like to spray the pan on the bottom and sides first to help keep the paper in place.
Then, pour the peanut butter cake batter into the center of the pan and use a spatula to spread it out, so that it reaches all four corners and is sitting in a roughly even layer.
Bake at 350°F for 25-30 minutes until you see some browning on top or a toothpick comes out clean.
Cool Before Frosting
Allow the cake to cool before you add your frosting of choice. You can keep it in the pan (I usually just serve it up right from there!) and place it on a cooling rack. For quicker cooling, remove the cake from the pan and place on a platter or directly on the cooling rack.
Once cooled, spread an even layer of frosting across the cake. You can decorate with some chopped peanuts (as pictured below), a piped frosting design, sprinkles, etc!
Alternatively, you can leave it as is. Serve it with a scoop of peanut butter, a dollop of whipped cream or cool whip, a scoop of ice cream, or even some butter.
Then, you can slice your cake into individual square pieces.
How to Properly Store Leftover Peanut Butter Sheet Cake
This peanut butter cake on its own (unfrosted) will last up to 5 days at room temperature or up to 10 days in the refrigerator.
However, if you frost the cake, you will have to keep in mind the storage instructions and recommendations for the frosting as well.
You can easily freeze this cake in a freezer-safe bag for about 6 months. Just thaw before enjoying.
Moist One-Bowl Peanut Butter Sheet Cake
SAVE RECIPE TO COLLECTION PIN PRINT RATEEquipment
- Hand Mixer or Stand Mixer
Ingredients
- ¾ cup vegetable oil (or canola oil)
- ¾ cup smooth creamy peanut butter (use one that doesn't separate and require stirring, my go-to here is Jif)
- 1 cup light brown sugar (tightly packed)
- 3 large eggs
- 2 teaspoons vanilla extract
- 1 ¼ cup milk of choice (any percentage of dairy or unsweetened, unflavored nondairy milk works)
- 2 cups all-purpose flour
- 2 tablespoons cornstarch
- 3 teaspoons baking powder
Instructions
- Preheat the oven to 350°F and line a 9×13-inch sheet pan with parchment paper.
- To a large mixing bowl, add the oil, peanut butter, and brown sugar and cream together with hand mixer on high.¾ cup vegetable oil, ¾ cup smooth creamy peanut butter, 1 cup light brown sugar
- Add the eggs and beat again to combine.3 large eggs
- Add the vanilla extract and milk and mix on low until smooth.2 teaspoons vanilla extract, 1 ¼ cup milk of choice
- Add the flour, cornstarch, and baking powder and beat one last time until smooth. Use a rubber spatula to push in any dry ingredients clinging to the sides of the bowl.2 cups all-purpose flour, 2 tablespoons cornstarch, 3 teaspoons baking powder
- Transfer the batter to your prepared sheet pan and use a spatula to spread it out into all four corners. The batter should be in a roughly even layer.
- Bake on the top rack for 25-30 minutes until a toothpick comes out clean. Cool completely before frosting. Try it with this peanut butter cream cheese frosting (as pictured) or this chocolate cream cheese frosting!
Pro Tips
- This cake can be frosted or served as is. It’d great simply with butter, whipped cream, or ice cream!
