Prepare the crust: Place 14 Oreo cookies in a food processor and pulse until fine crumbs form. Reserve the remaining 2 cookies for garnish.
Mix the butter into the crumbs: Pour the melted butter over the Oreo crumbs and pulse until the mixture resembles wet sand.
Press the crust: Press the crumb mixture firmly into the bottom and up the sides of a 9-inch pie plate. Place the crust in the freezer for 10 minutes to set.
Make the filling: Crush the remaining 2 Oreo cookies coarsely by hand or with a rolling pin.
Combine filling ingredients: Gently fold the crushed Oreos into the thawed whipped topping until evenly mixed.
Fill the pie: Spoon the filling evenly into the chilled crust.
Chill: Cover the pie loosely with plastic wrap and refrigerate for at least 4 hours, or until firm.
Serve: Slice and serve cold.
Notes
For a richer flavor, use cream cheese in place of half the whipped topping, softened first.
If you do not have a food processor, place cookies in a large zip-top bag and crush them with a rolling pin.
You can substitute the butter with 6 ounces of melted white chocolate for a different texture.