Crush cookies, set aside 1/2 cup for garnish. Mix remaining crumbs with margarine. Press into 9x13 pan. Refrigerate one hour. Mix cream cheese, powdered sugar and 1 carton whipped topping. Spread over crust and refrigerate one hour. Combine pudding mix, milk and vanilla and mix according to package directions. Spread over cream cheese layer and refrigerate one hour. Top with remaining carton whipped topping. Sprinkle reserved cookie crumbs on top. Keep refigerated.