Whisk together 1 cup of sugar, flour, and salt in a medium saucepan.
Whisk the milk and egg yolks together.
Cook the mixture, whisking continuously, in the saucepan over medium-high heat until it thickens.
It needs around five minutes.
Turn off the heat and then whisk in the vanilla extract.
Within a 4-quart casserole, layer bananas and vanilla wafers. Cover with custard.
Repeat to make a second layer of wafers, bananas, and custard.
Beat the egg whites at medium speed in a large bowl until frothy.
After sprinkling the 1/2 cup of sugar, whip the mixture until it is stiff and glossy.
Decorate with the meringue on top of the custard.
For 15 minutes, bake or until the meringues get golden brown in color.
Serve hot!