Combine graham cracker crumbs with melted butter. Press firmly into the bottom and up the sides of a 9-inch pie dish. Refrigerate while preparing the filling.
In a large bowl, beat peanut butter and cream cheese until smooth. Add powdered sugar and vanilla; mix until creamy.
Gently fold in the thawed whipped topping until incorporated. Do not overmix.
Crush 3 candy bars and fold into the peanut butter mixture.
Pour filling into the chilled crust and smooth the top.
Crush the remaining Butterfinger bar and sprinkle over the pie.
Refrigerate for at least 4 hours or overnight.
Slice with a hot, clean knife for neat servings.
