In a large bowl mix the cake mix and pumpkin puree until a smooth batter forms.
Pour into a sprayed 9X13 inch baking dish.
Bake at 350° according to package directions.

Let the cake cool for about 10 minutes after baking.
Using the bottom of a wooden spoon, poke holes all over the cake.

Pour the sweetened condensed milk over the cake, filling the holes.
Refrigerate 30 minutes.

Spread the cool whip over the top of the cake.
Sprinkle with Heath bits, and drizzle caramel over the top.
Refrigerate for 3-4 hours, or overnight.