Crush 48 Oreos in large Ziploc bag using a rolling pin or in a food processor. Set aside ⅓ of the crumbs to use later.
Mix ⅔ of the Oreo crumbs with butter and press onto bottom of 9×13 inch pan. Set aside
In a large bowl, add cream cheese, sugar, and vanilla and beat with a mixer until blended. Fold in whipped cream and most of the crumbs you had set aside.
Spoon the mixture over crust.
Sprinkle with the remaining cookie crumbs.
Refrigerate 4 hours, or until firm.