When cake is finished baking, let it cool off for about five minutes and then poke holes in it all over the top.
Pour the whole can of sweetened condensed milk over the top of the cake. Then pour some chocolate syrup and caramel syrup all over the top as well (you can just this according to taste).
Cover the cake and put it in the fridge to cool.
When cake is cool and all of the milk and syrups are soaked in take the Cool Whip and spread it all over the top.
Drizzle more chocolate syrup and caramel syrup all over the top as well. Then sprinkle on the Butterfinger Pieces!