In a medium bowl, mix together sugar, salt and flour.
In a separate medium bowl, whisk together milk and egg yolks until combined. Pour milk-and-egg mixture into saucepan/double boiler and heat on medium-high.
Sift in dry ingredients (or mix in 1/2 cup at a time if not using sifter), stirring mixture with a wooden spoon continuously until desired pudding consistency is met (usually 35-45 minutes; the longer you stir, the thicker it will become. It will also thicken a smidge when cooled.) Remove from heat, and add vanilla extract.
Fill serving bowl by alternating layers of bananas, custard and wafers, reserving 1/4 of wafers for garnish. Finish with a smooth custard layer on top. Crush remaining wafers to garnish.
Serve hot or chilled.
*Notes: My Grandma Scudder always made us the best homemade banana pudding. She passed away and never wrote down her recipe. It took nearly five years of many taste tests and complete fails, but I finally figured her recipe out and hit the nail on the head! Family approved. I have noticed this custard absorbs flavor, which is why I suggest stirring it with a wooden spoon. I do not recommend putting this in a metal serving dish due to a metallic taste. Glass or ceramic works best.