Spread caramel topping onto bottom of crust. Reserve 8 nuts for garnish. Coarsely chop remaining nuts; sprinkle over caramel topping.
Beat pudding mixes and milk with whisk 2 min. Stir in 1 cup COOL WHIP; pour into crust. Refrigerate 2 hours or until firm.
Microwave chocolate squares and remaining COOL WHIP in microwaveable bowl on HIGH 1 min.; stir until blended. Spread over pie. Top with reserved nuts(arranging one pecan half per slice). Let stand 10 min. before serving.