1Here's what you do:
Bake the cake according to the directions on the package.
When the cake comes out of the oven, poke it a bunch of times with the end of a wooden spoon to make a holes. The holes don't have to go all the way through the cake... just about 3/4 deep.
When the cake cools, pour the butterscotch topping over the cake... you will see it collect into the holes, creating yummy wells of deliciousness.
At this point, you can let it sit until you're ready to serve. (if you're making this the day before, this is when you'd wrap it up with saran wrap, stick it in the fridge, then go to bed...oh - may as well put the cool whip in the fridge at this point to thaw, too)
**Don't forget to thaw the Cool Whip!**
Spread Cool whip on top of butterscotch-soaked cake.
Sprinkle Heath Bar toffee bits on top.
3I've noticed if you let the Heath Bar sit on the cake longer before eating, they don't stay crunchy. so best to wait til the last minute before adding the heath bar.