In a medium-size mixing bowl, whisk together the evaporated milk, granulated sugar, flour and salt until dissolved.
On the stove top in a heavy bottomed saucepan over medium-high, warm the evaporated milk mixture.
In the same mixing bowl, whisk the egg yolks with the half & half. Whisk into the warmed evaporated milk mixture.
Cook stirring constantly for 10-15 minutes over medium heat until the flour has cooked and the custard has thickened. Once thickened remove from the heat and whisk in 2 tablespoon of butter and 1 tablespoon of pure vanilla. Set aside
Layer the bottom of a 7 x 11-inch oven safe dish with vanilla wafers. Top with banana slices. Cover with ½ of the custard. Repeat ending with custard.
Whip the 6 reserved egg whites with the vanilla, and cream of tarter. Sweeten with granulated sugar.
Whip for 3-5 minutes or until stiff peaks form. Spread the meringue on top of the banana pudding.
Set the oven to broil to toast the top until golden.
Garnish the edge with vanilla wafers, if desired.