MELT 4 Tbsp. butter; pour into medium bowl. Stir in wafer crumbs and sugar. Reserve 2 Tbsp. for later use; press remaining crumb mixture onto bottom and up side of 9-inch pie plate.
MICROWAVE chocolate and remaining butter in microwaveable bowl on HIGH 1 min. or until butter is melted; stir until chocolate is melted and mixture is well blended. Drizzle over bottom of crust; top with bananas.
BEAT pudding mix and milk with whisk 2 min.; pour over bananas. Refrigerate 4 hours. Top with COOL WHIP and reserved crumb mixture just before serving.
