In a 9 inch, round, spring form pan, place a layer of Oreo cookies. Break cookies in half or quarters to fill in bottom of pan where needed. Set aside.
Using a hand or stand mixer, blend cream cheese and condensed milk until smooth. Fold in 8 oz (1 tub) of Cool Whip. Spoon cream mixture over cookies. Add a second layer of cookies (you should have several cookies left over) and repeat with cream layer. Cover and place in refrigerator for 12 to 24 hours.
Remove cake from refrigerator and top with 8 oz. of Cool Whip. Remove cream filling from 8 to 10 cookies. Place cookies in a ziptop bag and crush. Sprinkle cookie crumbles on top of cake. Remove ring from cake pan and serve immediately.
*** This cake can be made in a 9x13 inch dish if no spring form pan is available.