Chop 15 cookies coarsely for the filling.

Finely crush the remaining cookies and mix with the butter. Press the mixture onto the bottom of 13x9-inch pan. Refrigerate until ready to use.

Beat cream cheese, sugar and vanilla in large bowl with mixer until blended. Gently stir in cool whip and coarsely chopped oreos; spoon over crust.

Refrigerate 4 hours or until firm.