Combine sugar, flour and salt in the top of a double boiler, stir in milk. Cook over boiling water, stirring until thickened.
Beat egg yolks and gradually stir into hot mixture. Return to double boiler; cook 5 minutes, stirring constantly.
Remove from heat, add vanilla.
Line one quart casserole with Bud's Best Vanilla Wafers and top with sliced bananas. Pour 1/2 portion of custard over bananas. Repeat, ending with custard on top.
Beat egg whites stiff but not dry. Gradually add ¼ cup sugar and beat until mixture forms stiff peaks. Pile on top of pudding.
Bake in preheated 425 degree oven for 5 minutes. Serve warm or chilled.