For the custard, add the egg yolks, 1 cup sugar, milk, flour, salt and vanilla in a pot over medium heat. Simmer until thick like pudding. Remove from heat and let cool. It will thicken even more as it cools.
For the meringue, beat egg whites and salt with a hand mixer until frothy. Add the sugar one tablespoon at a time, mixing between until all the sugar is added and the meringue has stiff peaks. Lastly, add the vanilla and gently fold in with a spatula.
To assemble, layer the bottom of the dish with vanilla wafers. Layer half of the sliced bananas on top of the wafers. Spread half of the custard over the wafers and bananas. Repeat these three steps using the remainder of the wafers, bananas and custard. Top with the meringue by plopping dollops then gently spreading the dollops around.
Bake for 15 minutes or until the meringue has browned peaks. Store in the refrigerator after it has cooled.