Peanut Butter Sheet Cake

5 from 1 vote

This Peanut Butter Sheet Cake is a super moist, tender cake with smooth and creamy peanut butter frosting on top. It's easy to whip up and loved by all!

Prep Time20

Cook Time25

Cool Time1

Total Time1 45

Course: Dessert

Cuisine: American

Keyword: sheet cake

Servings:

Calories: 342kcal

Author: Kelsey Byrnes

Equipment

One 9x13-inch pan

Ingredients

Peanut Butter Cake

2 cups flour
1 cup sugar
1 cup brown sugar
1/4 teaspoon salt
1 teaspoon baking soda
1 cup butter I use salted butter
1 cup water
1/2 cup creamy peanut butter
1/2 cup buttermilk*
1 teaspoon vanilla
2 eggs

Frosting

1/2 cup butter softened
1 cup creamy peanut butter
2 cups powdered sugar
1 teaspoon vanilla
2-3 tablespoons milk

Instructions

Make the Cake

Preheat oven to 350℉ and grease a 9x13-inch pan with cooking spray.
Add the flour, sugar, brown sugar, salt and baking soda to a large bowl; stir and set aside.
2 cups flour, 1 cup sugar, 1 cup brown sugar, 1/4 teaspoon salt, 1 teaspoon baking soda
Add the butter and water to a saucepan; bring to a boil then remove from the heat.
1 cup butter, 1 cup water
Stir the peanut butter into the water/butter mixture until smooth.
1/2 cup creamy peanut butter
Pour the peanut butter mixture over the dry ingredients and stir to combine.
In a small bowl, whisk together the buttermilk, vanilla and eggs. Pour over the batter and stir to combine.
1/2 cup buttermilk*, 1 teaspoon vanilla, 2 eggs
Pour the batter into the prepared pan and spread to an even layer.
Bake for 25-30 minutes or until a toothpick pressed into the center of the cake comes out clean or with just a few moist crumbs.
Let cool for an hour.

Make the Frosting

Add the butter and peanut butter to a mixing bowl.
1/2 cup butter, 1 cup creamy peanut butter
Use a hand mixer (or a stand mixer) to mix until smooth.
Add about 1/2 of the powdered sugar and the vanilla; stir until smooth.
2 cups powdered sugar, 1 teaspoon vanilla
Add the remaining powdered sugar and 2 tablespoons of milk.
2-3 tablespoons milk
Beat for 1 minute, until smooth and creamy! Add an additional tablespoon of milk, if needed.
Spread over the cooled cake.

Notes

Easy Buttermilk Substitute: Add 1 and 1/2 teaspoons of vinegar to a liquid measuring cup. Pour in enough milk to make 1/2 cup total. Give it a stir and proceed with the recipe!

Peanut Butter: I do not recommend using natural peanut butter for this recipe.

Pan Size: This recipe calls for a 9x13-inch pan. You can opt to make it in a sheet pan or a jelly roll pan if you choose to. However, please note that the baking time will be significantly shorter and the cake will be more thin.

Nutrition