Mix together cream cheese, sugar, and milk. When adding the milk you may not need the all of it to make it smooth. After completely mixing it together and you have no lumps then add in 8 oz. of Cool Whip.
Now crush up the bag of Oreo Cookies and put 1/3 of the cookie aside for topping. Then add the rest of the cookies to the mixture. Use a spoon to mix the cookies in.
Add the mixture to the pie crust and refrigerate for 2 hours.
After 2 hours add the rest of the Cool Whip and then top with the rest of the Oreo Cookies.