Prepare the crust: Mix the Oreo cookie crumbs and melted butter in a medium bowl until combined. Press the mixture firmly into the bottom and up the sides of a 9-inch pie plate. Place the crust in the freezer while you prepare the filling.
Make the cream cheese base: In a large bowl, beat the softened cream cheese, powdered sugar, and vanilla extract until smooth. Fold in half of the thawed whipped topping until just combined. Set aside.
Prepare the pudding: In a separate bowl, whisk together the instant chocolate pudding mix and cold milk for two minutes until the mixture begins to thicken. Let it stand for five minutes.
Combine the filling: Gently fold the thickened chocolate pudding into the cream cheese mixture until uniform in color. Then, gently fold in the remaining half of the thawed whipped topping.
Assemble the pie: Pour the filling evenly into the chilled Oreo crust.
Chill: Cover the pie loosely with plastic wrap and refrigerate for at least 4 hours, or until the filling is firm.
Serve: Before serving, sprinkle the top evenly with the crushed Oreo cookies. Slice and serve cold.
Notes
You can substitute store-bought Oreo crumbs to save time.
For a firmer crust, chill the crust mixture for 10 minutes before adding the filling.
If you prefer a richer chocolate flavor, use chocolate milk instead of regular milk when making the pudding.