Prepare your cake mix as directed on box
Once your cake is cooked, poke several holes in the top of the end of a spoon
Let your cake cool for 30 minutes
Mix together your sweetened condensed milk and your caramel sauce and pour over your cake and into your holes
Now using a hand mixer, beat your heavy whipping cream in a mixing bowl for several minutes until it starts to thicken
Once your heaving whipping cream thickens, add in your powdered sugar and beat for another several minutes
Spread your whipped cream over your cake with a spatula
Top off with your crushed Butterfinger, slice and enjoy!