Bake the cake according to package directions in a 9x13 baking pan.
Poke holes into the top of the cake using the end of a wooden spoon or a large meat fork.
Reserve about ¼ cup of ice cream topping for drizzling on top of the cake.
In a small bowl, combine the remaining ice cream topping with the sweetened condensed milk. Mix well.
Pour this mixture over the top of the cake, spreading if necessary to cover the whole cake.
Spread the Cool Whip over top the cake.
Sprinkle with chopped Heath bars and drizzle with the remaining ice cream topping.
Chill until serving.
If you can’t find German chocolate cake, just chocolate is fine.
If you can’t find that specific brand of ice cream topping, use an equal mix of caramel and butterscotch.
If you'd like a smaller amount of Cool Whip on the cake, you may just get by with 8 ounces.
The calories shown are based on the cake being cut into 15 pieces, with 1 serving being 1 slice of cake. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information.**