In a large mixing bowl, whisk together the sugar, cornstarch, and egg yolks until well combined. Whisk in 1 cup of the milk to the sugar mixture.
Place 2 cups of milk into a medium saucepan and bring it up to a boil.
Slowly whisk the hot milk into the sugar mixture. Transfer the mixture back into the pot and cook over medium heat until it thickens enough to coat the back of a spoon, stirring the whole time. Remove the pot from the stove, stir in the butter, and half the vanilla. Allow the pudding to cool.
Spread 1/3 of the pudding into the bottom of a 1 ½ quart casserole pan or an 8x8 pan. Add a layer of vanilla wafers and a layer of sliced bananas. Repeat this another time, ending with an extra layer of pudding.
In a medium mixing bowl, beat the heavy cream, powdered sugar, and the remaining vanilla until you have medium peaks.
Spread the whipped cream over the top of the pudding and sprinkle the top with some crushed wafers and banana slices.
Notes
Storage:
To Store: Store your pudding in an airtight container or cover the casserole pan in plastic wrap. You can keep it in the refrigerator for up to four days.
Tips:
If you don’t want to serve this in a casserole pan, you can also make it in a trifle bowl or individual cups.
Cool whip is a great substitute for the homemade whipped cream, although it will taste a bit sweeter.
Don’t use overripe bananas for this pudding because they’ll be too soft will brown too quickly.
To prevent the bananas from browning too quickly, you can toss them in a little lemon juice. Make sure you also cover the banana layers completely with pudding to seal out the air.