6 Tbsp. margarine, divided
25 Nilla Wafers, finely crushed (about 1-1/4 cups crumbs)
2 Tbsp. sugar
4 squares semi-sweet baking chocolate
2 large bananas, sliced
1 small pkg. vanilla pudding
1 ¾ cups cold milk
1 cup thawed Cool Whip
Melt 1/4 cup (4 Tbsp.) of the butter; place in medium bowl. Add wafer crumbs and sugar; mix well. Remove 2 Tbsp. of the crumb mixture; set aside for later use. Press remaining crumb mixture firmly onto bottom and up side of 9-inch pie plate; set aside. (A pre-made Nilla wafer crust may also be used.)
Microwave chocolate and remaining 2 Tbsp. butter in microwaveable bowl on HIGH 1 min. or until butter is melted; stir until chocolate is completely melted. Drizzle evenly onto bottom of crust; top with bananas. Set aside.
Prepare dry pudding mix with 1-3/4 cups cold milk as directed on package for pie; pour carefully over bananas. Refrigerate at least 4 hours or up to 24 hours. Top with whipped topping just before serving; sprinkle with reserved 2 Tbsp. crumb mixture.