1 pkg. devil's food cake mix
4 tbsp. butter
1/4 c. peanut butter
2/3 c. brown sugar
1 c. coarsely chopped salted nuts

Can use spice cake mix.

Prepare cake mix and bake in greased and floured 13"x9" pan, according to package directions. Cream together butter, peanut butter and brown sugar. Stir in nuts. Spread mixture over warm cake. Broil for 5 minutes or until frosting is bubbly. Serve warm.