Fluffernutter Bars

Fluffernutter Bars 1 box SuperMoist yellow cake mix 1/3 cup vegetable oil 1/3 cup peanut butter 2 eggs 1/4 cup butter, softened 1 jar (7 oz) marshmallow creme 1 teaspoon vanilla 2 cups powdered sugar 1 to 2 tablespoons milk Heat oven to 350ºF (325ºF for dark or nonstick pan). Grease bottom only of 9-inch square pan with shortening or cooking spray. In large bowl, beat cake mix, oil, peanut butter and eggs with electric mixer on low speed until smooth. Spread in pan. Bake 40 to 45 minutes or until toothpick inserted halfway between edge of pan and center comes out with just a few moist crumbs attached. Cool completely on cooling rack, about 1 hour. In medium bowl, beat butter and marshmallow creme with electric mixer on medium speed. Add vanilla. Gradually beat in powdered sugar. Thin with milk if necessary. Spread frosting on cooled bars. Cut into 4 rows by 4 rows.