Melt together caramels and 1/3 cup evaporated milk and set aside.
Mix together 1 package of the dry cake mix, 1/3 cup evaporated milk, nuts, and melted butter. Press half of the cake mixture into a 9x13 pan coated with cooking spray. Bake at 350°F for 6-8 minutes.
Take out of oven and sprinkle milk chocolate chips over baked cake. Next, spoon melted caramel over chocolate chips. Place the remainder of cake mixture by chunks over the top. Bake at 350°F for 16-18 minutes. Cool thoroughly and cut into squares.