Start by making your crust. Combine wafers and 1/8 cup sugar in a food processor. Melt your butter, and toss. With crumb crusts like this you end up pressing your crust in. Don’t worry about it being flaky, the cooling process and the addition of pudding later will firm it up like magic. Press the mixture into the pie pan until the bottom and sides are fully coated and there are no holes. Refrigerate at least 1 hour.
When your crust is nice and cool, go ahead and make your pudding. One box of pudding calls for 3 cups of cold milk, and you just whisk for two minutes. Let it set for about five minutes.
While it’s setting, slice bananas and line the pie crust with them. You want the whole pie to have bananas, even the sides, so don’t be shy. After you’ve done that, scoop the pudding into the dish and spread evenly over the bananas and crust.
Whisk heavy cream, remaining sugar, and vanilla extract until stiff peaks form. Scoop the whipped cream onto the top of the pie and spread it evenly. Refrigerate for at least 2 hours, and then serve.