In 3-quart saucepan, mix granulated sugar, cornstarch, and table salt. Gradually stir in the milk. Cook over medium heat, stirring constantly until mixture thickens and boils. Boil and stir about 1-minute.
Gradually stir at least half of the hot mixture into egg yolks, then stir back into hot mixture in saucepan. Boil and stir about 1 minute; remove from the heat. Stir in unsalted butter and the pure vanilla.
Pour the pudding into a large heatproof bowl. Cover the vanilla pudding and refrigerate about 1 hour or until chilled. Store covered in the refrigerator till needed.
To assemble dessert
Spread a thin layer of some vanilla pudding in a large casserole dish or if desired in separate dessert glasses.
Arrange a layer of vanilla wafers on top of the homemade vanilla pudding.
Thinly slice the bananas into rounds, about 1/8 inch thick, and arrange a layer of banana slices over the wafers.
Spread one-third of the remaining pudding over the bananas and continue layering the vanilla wafers, ripe bananas, and homemade vanilla pudding,
If desired top with homemade meringue or homemade whipped cream.
Refrigerate until ready for use or serve immediately.