Peanut Butter Sheet Cake

This Peanut Butter Sheet Cake is so decadent in flavor and unbelievably easy to make. In only an hour, this dessert is ready from start to finish to serve to a crowd. Watch out, we guarantee there will be no leftovers!

We’ve been making this Peanut Butter Sheet Cake for years, it happens to be a classic dessert recipe in the South. The rich peanut butter flavor is incorporated both into the cake as well as the frosting, making it extra flavorful in every bite. Plus, it’s made with affordable ingredients you probably already have in your pantry.

When we lived in Kentucky, this cake was always requested for our local church potluck. It was a favorite among the crowd and everyone always asked for the recipe! We love a great sheet cake recipe since they are easy to serve and to transport to an event too. Be sure to also try our viral White Texas Sheet Cake as well as our Chocolate Cake with Peanut Butter Frosting.

Why You’ll Love this Recipe

• Easy cake for beginner bakers. This peanut butter sheet cake is as simple as it gets. Just mix up common pantry ingredients for a delicious dessert that will disappear so quickly.
• No fancy equipment required. All you need is a couple of bowls and a saucepan to make this addicting dessert. The best part is cleanup is minimal too!
• Perfect for entertaining. We love to bring this cake to church potlucks, neighborhood gatherings, or make it for a family event. It’s simple to transport and easy to serve.

Ingredients

Scroll Down for Ingredient Amounts Listed in the Recipe Card Below

Cake Ingredients:

• Creamy peanut butter: The key to that great flavor, use your favorite brand here and avoid the natural kind.
• Salted butter: The fat that makes this cake so good, we love salted for this cake since it takes the flavor up another notch.
• Neutral oil: Such as canola, vegetable or avocado. It adds moisture to the cake.
• Self-rising flour: Provides the structure and also has baking powder in it to help the cake rise and be light in texture.
• Granulated sugar: Sweetens the cake just right.
• Whole buttermilk: Adds a tangy flavor and also tenderizes the cake batter.
• Large eggs: Bind the batter together.
• Vanilla extract: Gives nice floral and caramel notes in every bite.

Frosting Ingredients:

• Milk: The liquid that helps to make the frosting the right consistency.
• Creamy peanut butter: The base to any great peanut butter frosting.
• Vanilla extract: Makes the frosting even richer in flavor.
• Powdered sugar: Sweetens the frosting just right.

Tools You’ll Need

• Mixing Bowls
• Rubber Spatula
• Measuring Cups and Spoons
• Liquid Measuring Cups
• Small Saucepan
• 15×10 Sheet Pan

How to Make Peanut Butter Sheet Cake

1. Preheat oven to 350°F. Grease a 15×10-inch sheet pan with butter or nonstick spray.
2. In a medium saucepan over medium heat, combine peanut butter, water, butter, and oil. Bring to a boil, then turn off the heat.

3. In a large mixing bowl, whisk together self rising flour and sugar. Add the hot peanut butter mixture, and mix until smooth.

4. In a small bowl, whisk together eggs, buttermilk and vanilla extract. Add this mixture to the peanut butter mixture, and stir just until combined.

5. Pour the batter into the prepared sheet pan, spreading evenly. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs. Allow the cake to cool at least 20 minutes before adding the frosting.

6. For the frosting, in a medium saucepan, combine milk, peanut butter, and vanilla. Once melted and fully combined, turn off the heat and stir in powdered sugar until smooth. Spread on the slightly cooled cake. Slice and serve.

Expert Tips

• If you don’t have self rising flour, don’t worry it’s so simple to make. To substitute 2 cups self-rising that’s in this recipe, you’ll need to combine 2 cups of all purpose flour with 1 tablespoon of baking powder and 1/2 teaspoon of salt.
• Be sure to use regular creamy peanut butter and not the natural kind. The natural kind is runnier in texture and will not work correctly in the cake.
• Cool the cake layer before adding the peanut butter frosting. This is key or your frosting will run everywhere.
• We make our peanut butter frosting for this cake on the stovetop, this helps make the peanut butter easier to spread and also dissolves the powdered sugar evenly for the perfect sweet and glossy top.
• Frosting Tip: Too thick? Add another splash of milk and mix again until combined and the right consistency. If too loose, then just add more powdered sugar to thicken it.

Storage

Store any leftover peanut butter sheet cake in an airtight container at room temperature for up to 3 days. You can freeze this cake, but we just can’t guarantee it will be the same texture once it thaws.

Frequently Asked Questions

More Easy Dessert recipes

• Granny Cake
• White Texas Sheet Cake
• Peaches and Cream Cake
• Lemon Coconut Cake