1 german chocolate cake mix
1 can sweetened condensed milk
1 jar caramel ice cream topping
1 (8oz) container cool whip, thawed
2 Butterfinger candy bars, coarsely chopped
Mix up cake batter and bake in a 9x13 baking pan (or glass dish) according to package directions. As soon as the cake comes out of the oven poke holes in the top of it using a fork.
Combine sweetened condensed milk and caramel topping in a 2-cup glass measuring cup (this makes it easy to pour). Pour about half of the caramel mixture slowly over cake. Use a rubber spatula to spread the mixture evenly over cake. Wait about 10 minutes for the cake to soak up the caramel, then pour remaining mixture over the cake.
Cool cake completely.
Spread cool whip evenly over cooled cake, then sprinkle Butterfinger pieces on top. Cover and refrigerate for several hours or overnight.
This cake really really rich, so you'll want to be sure to cut small pieces! Refrigerate leftovers.