Chocolate Carmel Layer Bars

1pkg german chocolate cake mix 1/3 Cup evaporated milk 3/4 cup softened margarine 1 cup nuts (optional) Mix cake mix, milk and margarine. Add nuts and press 1/2 of mixture into greased and floured 9-13 inch pan. Bake 6 min at 350. 14 oz pkg light caramels 1/3 cup evaporated milk 3/4 large pkg chocolate chips - Melt caramels with milk over low heat, stirring often. Spread over baked crust. Sprinkle chocolate chips over caramel layer. Top with remaining cake mix. Bake for 15-20 min. Cool slightly and then refrigerate 30 min to set caramel. Cut into bars. ENJOY!!!