Line 13x9-inch pan with foil, with ends of foil extending over sides. Finely crush 28 cookies; mix with butter. Press onto bottom of prepared pan.
Beat 1 pkg. cream cheese, 1 cup peanut butter, 3/4 cup sugar and 2 tsp. vanilla in medium bowl with mixer until blended. Fold in 1-1/2 cups (about half of tub) COOL WHIP; spread over crust. Freeze 15 min.
Melt 6 oz. chocolate as directed on package; cool 10 min. Beat with remaining cream cheese, sugar and vanilla in medium bowl with mixer until blended. Fold in 1 cup of the remaining COOL WHIP; spread over frozen layer in pan.
Microwave remaining chocolate and COOL WHIP in small microwaveable bowl on HIGH 45 sec.; stir until chocolate is completely melted and mixture is well blended. Drizzle over dessert.
Spoon remaining peanut butter into microwaveable bowl. Microwave 15 sec.; stir. Drizzle over dessert. Freeze 2 hours.
Break remaining cookies into small pieces; scatter over dessert. Use foil handles to remove dessert from pan before cutting into bars.