In a round Pyrex casserole dish, place a single layer of vanilla wafers. Add slices of banana in a layer on top.
Prepare the vanilla pudding according to the directions on the box. Let cool slightly then stir in vanilla extract.
Pour the slightly cooled vanilla pudding over the bananas and wafers.
Repeat the layers, ending with pudding on top.
Serve with whipped cream, crushed vanilla wafers, etc. If making your own pudding, use the leftover egg whites to make a meringue and top with that!
I used a 9x13 rectangular casserole dish, which used all of the ingredients above, and it made 2 wafer-heavy layers. Grace's casserole dish accommodates more layers, but possibly fewer of the ingredients.
If the pudding has started to thicken before pouring it into the casserole dish, it works just as well to spread it over the bananas and wafers. If the pudding is still boiling though, the bananas will turn brown.
If made a few hours before serving, the vanilla wafers absorb the moisture and become a cake-like texture.
Some have recommended using different types of cookies (Nutter Butters, gingersnaps, golden oreos, etc), and/or different flavors of pudding (caramel, etc.), but not banana pudding, since its flavor is quite artificial.