Preheat oven to 350 degrees.
Prepare cake mix as directed.
Pour half of the batter into a greased 9 x 13 inch pan.
Bake 15 - 20 minutes.
Melt caramels, butter, and milk together.
Pour over baked mixture.
Sprinkle chocolate chips and nuts over caramel mixture.
Pour remaining cake batter over top of all and bake 20 minutes at 250 degrees then 10 minutes at 350 degrees.