Preheat the oven to 350°F (175°C) and choose a 2-quart baking dish or similar shallow pan.
Warm 2 cups of Whole Milk in a saucepan over medium heat until it’s steaming but not boiling; keep it nearby for the custard.
In a separate bowl whisk together 1/2 cup All-Purpose Flour, 3/4 cup Granulated Sugar, and a pinch of Salt to combine the dry ingredients.
Gradually whisk the warm milk into the dry mixture until smooth, return the mixture to the saucepan, and cook over medium heat, stirring constantly, until it begins to thicken and coat the back of a spoon.
Temporarily remove a ladleful of the hot mixture and whisk it into 4 lightly beaten Egg Yolks to temper them, then whisk the egg mixture back into the pan and cook for another 1–2 minutes, stirring, until the custard is thick and glossy.
Take the custard off the heat and stir in 2 tablespoons of Unsalted Butter and 1 teaspoon of Vanilla Extract until smooth; press plastic wrap directly onto the surface to prevent a skin from forming and let it cool slightly.
Slice the Bananas into rounds and line the bottom of the baking dish with a single layer of Vanilla Wafers, then add a layer of banana slices and spoon over about one-third of the prepared custard; repeat to make two or three layers, finishing with the remaining custard on top.
Make the meringue by beating the Egg Whites with a pinch of Cream Of Tartar until soft peaks form; then slowly add another 1/2 cup of Granulated Sugar while continuing to beat until the whites are glossy and hold stiff peaks.
Spread the meringue over the assembled pudding, making sure to seal it to the edges of the dish so the custard won’t weep during baking; swirl the top for a pretty finish.
Bake in the preheated oven for 8–12 minutes, or until the meringue is lightly golden. Remove from the oven and cool to room temperature, then chill for at least 1 hour before serving to let the layers set.
