To make the pudding, in a medium saucepan over medium heat, whisk the sugar, flour, and salt together. Slowly whisk in the milk until combined and smooth and then stir constantly with a wooden spoon until the mixture comes to a low boil and thickens, about 7 minutes. Reduce the heat to very low.
While whisking, add about 1/4 cup of the hot milk mixture to the eggs. Whisk the egg mixture into the hot milk and cook, stirring constantly, until the mixture is very thick, 3 to 4 minutes. Remove from the heat and stir in the vanilla. Let stand until room temperature.
To make the pie, arrange half of the banana slices in a single layer over the crust. Spread half of the pudding evenly over the bananas. Lay the wafer cookies in a single layer on the surface of the pudding, followed by the remaining bananas. Spread the rest of the pudding evenly over the top.
In a small bowl, with a whisk or electric hand mixer, whip the cream, sugar, and vanilla together until soft peaks form. Spread the cream evenly over the pie. Sprinkle vanilla wafer crumbs over the top. Cover with plastic wrap and chill for at least 3 hours before serving.
To serve, slice the pie and garnish each slice with vanilla wafer crumbs.
Adapted from "The Comfort Table" by Katie Lee (C) Simon Spotlight Entertainment 2008. Provided courtesy of Katie Lee. All rights reserved.