1 pkg. yellow cake mix (your choice)
1/2 cup creamy peanut butter (do not use old fashioned or freshly ground)

Preheat oven to 350°F. Grease and flour two 9-inch diameter cake pans with 1 3/4 inch high sides.

Prepare cake according to package directions, beating in peanut butter. Divide between prepared pans.

Bake at 350°F until toothpick inserted into centers comes out clean, about 20 minutes. Cool cakes in pans on rack 10 minutes. Turn cake out onto racks and cool completely.

PEANUT BUTTER FROSTING:

3/4 cup chocolate syrup (Hershey's)
8 oz. semi-sweet chocolate
2 cups creamy peanut butter
1 cup confectioners' sugar
chopped peanuts
2 1/2 cups creamy peanut butter, divided (do not use old fashioned or freshly ground)
1/4 cup milk

Combine chocolate syrup and semi-sweet chocolate in heavy small saucepan. Stir constantly over low heat until chocolate is melted and mixture is smooth. Transfer chocolate mixture to large bowl. Stir in peanut butter, then confectioners' sugar, then milk. Continue stirring until smooth. Frost cake. Garnish with chopped peanuts, if desired.

Makes 1 (2 layer) frosted cake.