In a food processor, pulse the Oreo cookies for several minutes until fine crumbs. Add in melted butter and pulse until combined.
Press Oreo crumbs into the bottom and sides of a 9-inch pie plate. Set in the freezer while you make the pie filling.
In a mixing bowl, beat cream cheese with sweetened condensed milk and peanut butter until smooth and creamy.
Fold in Cool Whip and all but 2 Tablespoons of the crushed Butterfinger candy.
Pour mixture into the prepared pie crust. Sprinkle with remaining candy.
Cover with plastic wrap and refrigerate for at least 4 hours. Slice and enjoy.
Notes
Swap out the Oreo cookies for Nutter butter cookies to up the peanut butter flavor, if desired.
I suggest using a shelf stable peanut butter, like Jif or Skippy, with no layer of oil like natural peanut butters have on top. This gives your pie the best texture.
Store pie, covered with plastic wrap, in the refrigerator for up to 4 days.
Freeze pie in an airtight container for up to 3 months. Thaw in refrigerator overnight.