Caramel Fudge Cake

Preheat oven to 350 degrees. Spray a 13-by-9-inch baking pan with non-stick cooking spray.

Prepare cake mix according to package directions. Pour 2 cups batter into prepared pan. Bake 15 minutes. Remove cake from oven.

Meanwhile, in heavy saucepan over low heat, melt caramels and margarine with sweetened condensed milk, stirring until smooth. Spread evenly over cake. 

Spread remaining cake batter over caramel mixture. Top with nuts.

Bake 30 to 35 minutes longer or until cake springs back when touched lightly.