Prepare the base by combining graham cracker crumbs, cocoa powder, and melted butter in a bowl.
Bake the crust in a preheated oven for about 10 minutes.
Remove the crust from the oven and allow it to cool slightly before pouring the condensed milk over it.
Sprinkle the crushed Butterfinger evenly over the condensed milk, pressing down gently to adhere.
Drizzle the caramel sauce over the Butterfinger layer and sprinkle with optional chopped nuts.
Finish by covering with a layer of remaining crushed Butterfinger or a crunch topping, if desired.
Chill the bars in the refrigerator for at least 2 hours before slicing.
Once set, slice into bars and enjoy your Butterfinger Caramel Crunch Bars.