In top of double boiler, stir together 1/3 Cup of evaporated milk and all caramels (can be done in microwave)
Cook over hot water until smooth. Set aside
Stir together cake mix, butter, remaining evaporated milk and nuts. Press 1/2 dough into greased and floured 13x9x2" pan and bake at 350º for 6 minutes. Remove from oven
Sprinkle chocolate pieces on baked dough and top with caramel mixture. Crumble remaining dough over top. Return to oven and continue baking 15 to 18 minutes more. Cool and cut into bars
