Peanut Butter Sheet Cake with Peanut Butter Frosting

Just baked this heavenly Peanut Butter Sheet Cake with Peanut Butter Frosting! 🍰✨


  • 2 cups all-purpose flour
  • 2 cups sugar
  • 1/2 teaspoon baking soda
  • 1/4 teaspoon salt
  • 1 1/2 (12 tablespoons) sticks butter
  • 1 cup water
  • 1/2 cup peanut butter
  • 1/4 cup vegetable oil
  • 2 eggs
  • 1/2 cup buttermilk
  • 1 teaspoon vanilla extract


  1. Preheat oven to 350 degrees. Grease a 10x15x1 inch jellyroll pan.
  2. In a large bowl, whisk together flour, sugar, baking soda, and salt.
  3. Combine 1 1/2 sticks butter and 1 cup water in a medium saucepan and bring to a simmer. Stir to make sure all the butter is melted.
  4. Whisk 1/2 cup peanut butter and vegetable oil into the butter mixture. Stir into the flour mixture.
  5. Whisk together eggs, buttermilk, and vanilla extract. Stir into the flour mixture until well combined.
  6. Pour batter into the prepared pan.
  7. Bake for 22 to 26 minutes or until a toothpick inserted in the middle comes out clean. Let cool.

To make Frosting,

  1. Use an electric mixer to beat butter and peanut butter together until smooth.
  2. Add half of confectioners’ sugar and half of milk and beat until smooth.
  3. Add remaining confectioners’ sugar, milk, and the vanilla pudding mix and beat until smooth. Add a little more milk if necessary.
  4. Spread frosting on cake.

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