Preparation
Place butter in a greased 9-in. microwave-safe pie plate. Heat, uncovered, on high for q minute or until melted, turning once. Stir in crumbs and sugar; mix well. Press onto the bottom and up the sides of plate. Cook, uncovered, on high for 1-1/2 to 2 minutes or until crust is firm and holds together. Cool completely.
For filling, in a 2-qt. microwave-safe bow, combine sugar, flour and cornstarch. Gradually whisk in milk until smooth. Microwave, uncovered, on high for 9-10 minutes or until thickened, stirring every 2 minutes. Stir a small amount of hot liquid into egg yolks. Gradually return to the bowl, stirring constantly. Cook 1 to 1-1/2 minutes longer or until bubbly, stirring every 30 seconds. Stir in butter, vanilla and salt until butter is melted. Cool for 20 minutes, stirring several times.
Arrange bananas in crust. Top with filling. Cover and chill 8 hours or overnight. Top with whipped topping and additional bananas if desired.