Combine baking crumbs and butter; press onto bottom of 9-inch springform pan. Refrigerate 10 min.
Beat cream cheese, peanut butter and sugar with mixer until blended. Add half the chocolate; mix well.
Whisk in 1 cup whipped topping. Spoon over crust.
Refrigerate 3 hours.
Microwave remaining chocolate and whipped topping in small microwaveable bowl on HIGH 1 min.; cool slightly.
Pour melted chocolate mixture over cheesecake. Refrigerate until firm.
Run knife around rim of pan to loosen cake, then remove rim before cutting cheesecake into pieces to serve.