This peanut butter cake is the ultimate potluck dessert, a rich peanut butter sheet cake with peanut butter icing that’s made for sharing. It’s perfect for holidays, barbecues, or just an easy weekend treat.
This cake is great for sharing, and it's part of my larger list of desserts for a potluck.

Sheet cakes are probably my favorite type of cake recipes because they’re so easy to make, instead of having to worry about stacking a layered cake, or frosting a round cake.
This depression cake recipe is such a favorite around here, so I knew you’d also love this peanut butter sheet cake, too. And if you love the combination of peanut butter and chocolate, you’ll adore this chocolate peanut butter dump cake.
Frequently Asked Questions
Regular creamy peanut butter like Jif or Skippy works best. Natural peanut butter separates and can make the cake and icing oily, so save that one for your toast.
You can, especially in the cake, for little bits of peanut throughout. For the icing, stick with creamy so it stays smooth and spreadable.
Buttermilk keeps this cake tender and moist, so I don’t recommend skipping it. In a pinch, stir 1 tablespoon of lemon juice or white vinegar into a scant cup of milk, let it sit 5 minutes, and use that.
Yes. Wrap it well, frosted or unfrosted, and freeze up to 3 months. Thaw at room temperature before serving.
Absolutely, peanut butter and chocolate are a classic pair. Drizzle melted chocolate over the icing or add a layer of chocolate frosting.

Ingredients Needed:
I’ve provided some notes below about some of the key ingredients. The full recipe with a list of the ingredients and amounts can be found in the recipe card below.
Peanut butter icing on peanut butter cake is not subtle, and that’s the point. Browse more potluck cake recipes.

- Kosher salt - A little salt brings out the peanut butter flavor and keeps it from tasting flat.
- Unsalted butter - For richness and that classic buttery base. Salted works in a pinch-just skip the added salt.
- Creamy peanut butter - I use regular store-bought (like Jif or Skippy). Natural peanut butter will make the texture weird unless stirred very well.
- Buttermilk - Keeps the cake soft and moist. You can make your own: ½ cup milk + ½ tablespoon vinegar or lemon juice.
- Heavy whipping cream - Adds richness and makes the frosting extra smooth and fluffy. You can use whole milk or half and half if you want a thinner consistency.
How to Make Peanut Butter Sheet Cake
- Preheat your oven to 350°F. Prepare a 9 x 13-inch baking dish with nonstick cooking spray. Set it aside.

- Whisk together 2 cups all-purpose flour, 2 ¼ cups granulated sugar, 1 teaspoon baking soda, and ½ teaspoon kosher salt in a large mixing bowl.
- Combine 1 cup purified water, ½ cup (1 stick) unsalted butter, and ¾ cup creamy peanut butter in a medium saucepan over medium heat. Stir constantly until it comes to a gentle boil and everything is melted and smooth. Remove from heat.

- Pour the warm peanut butter mixture over the dry ingredients and stir until mostly combined. Add ½ cup buttermilk, 2 large eggs, and 2 teaspoons pure vanilla extract, and mix until smooth. Don't overmix.
- Pour the batter into your prepared pan and smooth it out evenly. Bake for 25 to 35 minutes, or until the center is set and a toothpick comes out clean.

- Once the cake is fully baked, remove it from the oven and let it cool completely in the pan on a wire cooling rack-this will take up to 1½ to 2 hours at room temperature. Don't rush it! If the cake is even a little warm, the frosting will slide right off.
How to Make Peanut Butter Icing

- About 15 to 20 minutes before you're ready to frost, prepare the buttercream. In a large bowl, beat 1 cup (2 sticks) softened unsalted butter and 1 cup creamy peanut butter together with a hand mixer or stand mixer until light and fluffy-about 2 to 3 minutes.
- Add 2 teaspoons pure vanilla extract and a pinch of salt, then mix in 4 cups powdered sugar, one cup at a time. Add ¼ cup heavy cream gradually, beating until the frosting is thick, smooth, and spreadable. Add more heavy cream if needed to thin the frosting or add more powdered sugar if needed to thicken.
- Once the cake is completely cool, use an offset spatula to generously spread the peanut butter frosting evenly across the top. If you like a thicker layer, pile it on…you've got plenty!

More Peanut Butter Cake Topping Ideas
For extra flair, top with chopped roasted peanuts, mini peanut butter cups, or even a drizzle of chocolate.
Recipe Tips
- Don't skip the buttermilk – it keeps the cake soft and tender with just the right balance of tang and richness.
- Type of baking pan – If you’re baking this in a glass 9×13 dish, keep in mind that glass retains heat more than metal. Your cake may take an extra 3-5 minutes to bake through. Start checking around the 25-minute mark, but don't be surprised if it needs closer to 35 minutes. A metal pan will give you slightly crisper edges, while glass tends to produce a softer, more even bake.
- Pipe the frosting on the cake first, then use an offset spatula to smooth out the frosting.

How to Store Leftover Cake
- Store any leftovers covered at room temperature for up to 3 days or in the fridge for up to 5 days. Once cooled, cover the sheet cake tightly with foil or plastic wrap and store at room temperature for up to 3 days.
- You can refrigerate it for up to 5 days, but bring it to room temperature before serving for the best texture.
- To make ahead, bake the cake a day in advance and store it covered. Make the frosting fresh and pour it on the next day to wow your guests with that fresh, glossy finish.
Related Recipes
If you love peanut butter desserts like this one, you’ll also love these:
Or if you finish this peanut butter cake and need something quick later, add some peanut butter to this mug cake!
Did you make this? I’d be so grateful if you left a “star” rating below to let me know what you thought! Then, the next time you need a quick and easy recipe, come back to Fantabulosity to browse all of my easy recipes!
Recipe
Peanut Butter Cake with Peanut Butter Frosting
Equipment
- mixing bowls
- Whisk
- Saucepan
- Wooden Spoon
- Measuring cups and spoons
- 9×13 baking dish or baking pan
- hand or stand mixer with paddle attachment
- rubber spatula
- wire rack
Ingredients
For the Peanut Butter Sheet Cake
- 2 cups all-purpose flour
- 2¼ cups granulated sugar
- 1 teaspoon baking soda
- ½ teaspoon kosher salt
- 1 cup water
- ½ cup unsalted butter 1 stick
- ¾ cup creamy peanut butter
- ½ cup buttermilk
- 2 large eggs
- 2 teaspoons pure vanilla extract
For the Peanut Butter Icing
- 1 cup unsalted butter 2 sticks, softened
- 1 cup creamy peanut butter
- 2 teaspoons pure vanilla extract
- 1 pinch kosher salt
- 4 cups powdered sugar
- ¼ cup heavy whipping cream
Instructions
How to Make the Peanut Butter Cake
- Preheat your oven to 350°F. Prepare a 9 x 13-inch baking dish with nonstick cooking spray. Set it aside.
- Whisk together 2 cups all-purpose flour, 2 ¼ cups granulated sugar, 1 teaspoon baking soda, and ½ teaspoon kosher salt in a large mixing bowl.2 cups all-purpose flour, 2¼ cups granulated sugar, 1 teaspoon baking soda, ½ teaspoon kosher salt
- Combine 1 cup water, ½ cup (1 stick) unsalted butter, and ¾ cup creamy peanut butter in a medium saucepan over medium heat. Stir constantly until it comes to a gentle boil and everything is melted and smooth. Remove from heat.1 cup water, ½ cup unsalted butter, ¾ cup creamy peanut butter
- Pour the warm peanut butter mixture over the dry ingredients and stir until mostly combined. Add ½ cup buttermilk, 2 large eggs, and 2 teaspoons pure vanilla extract, and mix until smooth. Don't overmix.½ cup buttermilk, 2 large eggs, 2 teaspoons pure vanilla extract
- Pour the batter into your prepared pan and smooth it out evenly. Bake for 25 to 35 minutes, or until the center is set and a toothpick comes out clean.
- Once the cake is fully baked, remove it from the oven and let it cool completely in the pan on a wire cooling rack-this will take up to 1½ to 2 hours at room temperature. Don't rush it! If the cake is even a little warm, the frosting will slide right off.
How to Make Peanut Butter Icing
- About 15 to 20 minutes before you're ready to frost, prepare the buttercream. In a large bowl, beat 1 cup (2 sticks) softened unsalted butter and 1 cup creamy peanut butter together with a hand mixer or stand mixer until light and fluffy-about 2 to 3 minutes.1 cup unsalted butter, 1 cup creamy peanut butter
- Add 2 teaspoons pure vanilla extract and a pinch of salt, then mix in 4 cups powdered sugar, one cup at a time. Add ¼ cup heavy cream gradually, beating until the frosting is thick, smooth, and spreadable. Add more heavy cream if needed to thin the frosting or add more powdered sugar if needed to thicken.2 teaspoons pure vanilla extract, 1 pinch kosher salt, 4 cups powdered sugar, ¼ cup heavy whipping cream
- Once the cake is completely cool, use an offset spatula to generously spread the peanut butter frosting evenly across the top. If you like a thicker layer, pile it on-you've got plenty!






















































































































































































































































































































































































































































































































