Caramel Fudge Cake
["1 (18 1/2 oz.) box chocolate cake mix", "14 oz. caramels", "1/4 c. margarine", "14 oz. sweetened condensed milk", "1 c. chopped walnuts"]
["Preheat oven to 350\u00b0.", "Prepare cake mix as directed.", "Pour 2 cups batter into greased 13 x 9-inch pan.", "Bake only 15 minutes."]
["chocolate cake mix", "caramels", "margarine", "condensed milk", "walnuts"]