1 stick butter, melted
1 Duncan Hines deluxe chocolate cake mix
3/4 c. creamy peanut butter
1 (7 oz.) jar marshmallow creme

Combine melted butter and dry cake mix. Reserve 1 1/2 cups of this mixture for top crust. Pat remaining crumb mixture into ungreased 13"x9"x2" pan. Top that layer with combined peanut butter and marshmallow creme and spread evenly. Spread remaining crumb mixture over that. Bake 20 minutes at 350 degrees and cool.