Mix one box of instant vanilla pudding with 2 cups of cold milk according to the package directions. Put in refrigerator to set. This usually takes 5 or more minutes.
Line a pie pan with nilla wafers in one single layer. Cut banana slices and place on top of the nilla wafers in a single layer.
If making homemade whipped cream- mix heavy cream, vanilla, and sugar with a hand mixer until stiff peaks form.
Gently fold the whipped cream into the pudding.
Add half of the pudding mixture on top of the nilla/banana layers. Spread out evenly in the pie pan. Add another layer of nilla wafers, then bananas, and finish with a layer of the rest of the banana pudding.
Top with crushed cookies or whipped cream. Serve immediately or cover and refrigerate until ready to serve. Can be made a day in advance but the cookies will be soggier and bananas will be browner.