Prepare cake batter and bake in 2 (9 inch)round pans as directed on package. Cool cakes in pans 10 min Invert onto wire racks, gently remove pans. Cool cakes completely.
Microwave chocolate and butter in small microwaveable bowl on high 2 min or until butter is melted. Stir until chocolate is completely melted. cool 5 minutes. Meanwhile, beat cream cheese an sugar in large bowl with mixer until blended. Gently stir in cool whip and crushed cookies
Place 1 cake layer on plate, spread with cream cheese mixture. Top with remaining cake layer. Spread top with chocolate glaze, let stand 10 min or until firm keep refrigerated.