My mom made this luscious cake in her later years and it's just as delicious now as then. I recently took it to a potluck and it just disappeared! I prefer to use dark chocolate chips.
The hardest part of this recipe is unwrapping all those caramels.
Heat oven to 350 degrees. If using a dark pan, heat oven to 325 degrees.
Mix cake according to package directions. Pour half the batter (2 cups) in a 9 x 13 greased and floured pan. (I use Pam Baking Spray.) Bake for 20 minutes.
While that is baking, put caramels, margarine, and milk in a sauce pan and heat, stirring, on top of stove until caramels are melted.
When the caramel mixture is cool but spreadable, pour over the cake that was baked. Sprinkle with chocolate chips and nuts. Add remaining cake dough and bake 30 minutes or until a toothpick comes out clean when inserted only to about 1/2" (so it doesn't go down into the caramel mixture).
Frost it with Betty Crocker (or other brand) Milk Chocolate Frosting. Store lightly covered.