How to Make It
Preheat oven to 325°.
Lightly spoon flour into a dry measuring cup; level with a knife. Combine flour, 1 1/4 cups sugar, and salt in a large saucepan, stirring with a whisk. Gradually add milk, stirring until smooth. Scrape seeds from vanilla bean, and add seeds and bean to milk mixture.
Cook over medium heat 12 minutes or until thick and bubbly, stirring constantly.
Place eggs in a large bowl, and gradually add hot milk mixture, stirring constantly. Place mixture in pan; cook over medium heat 2 minutes or until thick and bubbly, stirring constantly. Discard vanilla bean.
Place egg whites in a large bowl; beat with a mixer at high speed until foamy. Add 3/4 cup sugar, 1 tablespoon at a time, beating until stiff peaks form.
Arrange half of vanilla wafers in the bottom of a 13 x 9-inch baking dish. Arrange half of the banana slices over wafers. Pour half of custard over banana. Repeat procedure with the remaining wafers, banana, and custard.
Top with meringue, spreading evenly to edges of dish.
Bake at 325° for 20 minutes or until lightly browned. Serve pudding warm or chilled.