Triple fudge bars

1. Prepare frosting mix as directed on package.
Combine dry cake mix, 1/2 cup prepared frosting, water and egg.
Stir by hand until cake mix is moistened. Mixture will be stiff.
Put into 13x9 in. pan greased on the bottom, only.
Beat sour cream into remaining frosting. Spread over base.
Sprinkle with chocolate pieces and nuts.
Bake at 350 for 40-45 minutes. Top will be puffy. Chocolate chips do not melt.
Cool, cut into bars.