Peanut Butter Sheet Cake with Chocolate Frosting

The pairing of peanut butter and chocolate never disappoints, especially when its Betty Crocker SuperMoist yellow cake made with peanut butter and topped with chocolate frosting.

  • Prep Time 15 min
  • Total Time 1 hr 40 min
  • Servings 12


box Betty Crocker™ SuperMoist™ yellow cake mix
1 1/3
cups water
cup peanut butter
cup vegetable oil
teaspoon vanilla


cup butter
cup unsweetened baking cocoa
cup milk
teaspoon vanilla
3 3/4
cups powdered sugar

  • 1 Heat oven to 350°F (325°F for dark or nonstick pan). Spray bottom and sides of 13x9-inch pan with baking spray with flour.
  • 2 In large bowl, beat all cake ingredients with electric mixer on low speed 30 seconds, then on medium speed 2 minutes, scraping bowl occasionally. Pour into pan.
  • 3 Bake 20 to 25 minutes or until toothpick inserted in center comes out clean.
  • 4 In 2-quart saucepan, heat butter, cocoa and milk to boiling over medium heat. Remove from heat; stir in 1 teaspoon vanilla. Gradually add powered sugar, beating until mixture is blended and smooth. Pour frosting over warm cake.
  • 5 Cool completely in pan on cooling rack, about 1 hour. Cut into 4 rows by 3 rows.

Expert Tips

To make a thinner cake, use a 15x10x1-inch pan and reduce the baking time by 5 minutes.

To add even more peanut butter and chocolate flavor, top the cake with chopped chocolate-covered peanut butter cup candies.