Place the Butterfinger bars into a food processor and pulse until finely crushed.* Transfer to a mixing bowl. Finely crush the graham crackers in the food processor, then place them into the same mixing bowl as the crushed Butterfinger bars.
Add the brown sugar and butter and use a fork to toss everything together. Pour mixture into a greased 9-inch pie dish and evenly press the mixture along the bottom and up the sides of the dish. Place in the refrigerator while you work on the fillings.
Make the Whipped Cream (used for both pie fillings)
In the chilled bowl of a stand mixer fitted with the whisk attachment, beat the heavy cream until stiff peaks form. Transfer whipped cream to a separate bowl, and return mixing bowl to mixer.
Make the Peanut Butterscotch Filling:
Place the butterscotch chips and peanut butter in a medium microwave-safe bowl. Heat in the microwave for about 60 seconds. Remove, and stir until smooth. If still lumpy, heat in 10-second increments until mixture is completely smooth.
Transfer mixture to a stand mixer fitted with the paddle attachment, and beat in the cream cheese. Fold in one cup of the whipped cream (made earlier) until mixture is completely combined. Pour filling into the pie crust and smooth out evenly. Return pie to refrigerator.
Make the Butterfinger Cream Filling:
In the bowl of a stand mixer fitted with the paddle attachment, beat the cream cheese until smooth. Add the powdered sugar and continue beating until combined. Add the remaining whipped cream (made earlier), mixing until just combined. Fold in the chopped Butterfinger bars.
Spread filling on top of the peanut butterscotch filling, and place pie in the refrigerator for at least 4 hours, or overnight.
Make the Whipped Cream Border:
In the chilled bowl of a stand mixer fitted with a whisk attachment, beat the heavy cream until soft peaks form. Add the powdered sugar and vanilla, and continue beating until stiff peaks form. Transfer whipped cream to a large pastry bag fitted with a large star tip.
Pipe whipped cream along the edges of the pie. Insert chopped Butterfinger bars into the border. Slice and serve immediately, or store in a covered container in the refrigerator for up to 5 days.