Peanut Butter Sheet Cake with Chocolate Frosting

By brownbox

Ingredients

• 1 box Betty Crocker® SuperMoist® yellow cake mix
• 1 1/3 cups water
• 1/3 cup peanut butter
• 1/3 cup vegetable oil
• 3 eggs
• 1 teaspoon vanilla
• 1/2 cup butter
• 1/4 cup unsweetened baking cocoa
• 1/4 cup milk
• 1 teaspoon vanilla
• 3 3/4 cups powdered sugar

Preparation

Step 1

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.