Tip: Another recipe with the exact-same name "Butterfinger CAke" ranks higher.
Make cake as directed on the box in an oblong baking pan. Let cool completely. Then punch holes in the cake with a straw. Pour milk over the cake. Next pout caramel topping over the milk. Sprinkle 1/2 of the crushed butterfingers over the caramel
(layering) Cover with cool whip for the final topping. Refrigerate the leftovers.