On a lightly floured surface, roll dough to a 1/8-in.-thick circle; transfer to a 9-in. pie plate. Trim to 1/2 in. beyond rim of plate; flute edge. Refrigerate 30 minutes. Preheat oven to 425°. Line crust with a double thickness of foil. Fill with pie weights, dried beans or uncooked rice. Bake on a lower oven rack until edges are golden brown, 20-25 minutes. Remove foil and weights; bake until bottom is golden brown, 3-6 minutes longer. Cool on a wire rack., In a large saucepan, combine sugar, cornstarch, salt and milk until smooth. Cook and stir over medium-high heat until thickened and bubbly. Reduce heat; cook and stir 2 minutes longer. Remove from heat. Stir a small amount of hot filling into eggs; return all to pan. Bring to a gentle boil; cook and stir 2 minutes longer., Remove from heat. Gently stir in butter and vanilla. Press plastic wrap onto surface of custard; refrigerate, covered, 30 minutes., Spread half of the custard into crust. Slice bananas; arrange over filling. Pour remaining custard over bananas. Spread with whipped cream. Refrigerate 6 hours or overnight.