Finely crush Oreos in a food processor. Add all but ¾ cup to a large bowl. Add melted butter to bowl and stir until mixture starts to hold together. Pour mixture into 9”-x-9” baking dish and pack into an even layer.
In a medium bowl, whisk together pudding mix and milk until thickened, then refrigerate for 10 minutes to firm up.
In a large bowl using a hand mixer, beat cream cheese and powdered sugar together until no lumps remain.
In another large bowl, beat cream until stiff peaks form.
Fold pudding into cream cheese mixture, then fold in whipped cream until just combined. Pour mixture over Oreo crust and smooth with an offset spatula. Top with reserved ¾ cup crushed Oreos.
Refrigerate until well chilled, at least 3 hours and up to overnight.