Chocolate Peanut Butter Cake with Baby Ruth Frosting

1 (18.25 ounce) box chocolate cake mix
1 cup creamy peanut butter

Baby Ruth Frosting:
6 (2 1/2 ounce) Baby Ruth candy bars, chopped
1 /2 cup (1 stick) butter or margarine
1 cup evaporated milk
1 cup granulated sugar
1 cup sweetened flaked coconut (optional)
1/2 cup dry-roasted peanuts, chopped
2 large egg yolks

Heat oven to 350 degrees F. Lightly grease and flour 13 x 9-inch baking pan.

Prepare cake batter according to package directions, adding peanut butter before mixing. Pour into prepared pan. Bake for 30 to 40 minutes or until wooden pick comes out clean. Cool completely in pan on wire rack.

Place chopped Baby Ruth and butter in medium, heavy duty saucepan. Cook over low heat, stirring frequently, for about 10 minutes or until thickened. Cool in refrigerator for 30 minutes. Stir. Frost cake with Baby Ruth frosting. Refrigerate cake until ready to serve.