Combine chocolate graham cracker crumbs, 1/2 c sugar and 12 T of melted butter. Press into a 13 x 9-in pan. Chill.
Whip the whipping cream until stiff peaks form; refrigerate.
In a large mixing bowl, beat cream cheese until smooth. Gradually add 1 1/3 c. sugar; blend thoroughly. Fold in the broken Oreos along with the chilled whipped cream.
Spread filling evenly into crust, smoothing top and spreading to edges. Cover and refrigerate 4 hours or overnight.
