In a medium Pot mix flour and salt and then gradually pour milk in and sweetened and condensed milk and keep stirring and keep stirring and then add your two egg yolks and stir for about 8 minutes until it thickens up.
When it thickens up, add 2 teaspoons of vanilla extract and stir it in. Use a 2 quart Pyrex dish and start layering the bottom with Banana Slices, then pour some of the custard over the Bananas then layer with Vanilla Wafers and continue in this order until you have used all your Bananas, custard, vanilla wafers.
Then add your 4 egg whites in a mixing bowl and mix with a mixer then stop. Then add 2 teaspoons of sugar and mix until a stiff peak form. Then spread over the top of your Banana pudding. Then bake in the oven for at least 25 minutes on 325 degrees. Then take out of oven and let cool, then serve.