In a mixing bowl, combine vanilla wafer crumbs and melted unsalted butter.
Portion the crumbs into 28 2-ounce plastic cups using a small cookie scoop Use one of the plastic cups to press the crumbs into the bottom of the cup.
In a large mixing bowl, whisk together instant banana pudding mix, milk, and vanilla extract. Chill in the refrigerator for five minutes.
Add heavy cream to the banana pudding mixture and whip with an electric hand mixer on medium-high speed until it has a thick and fluffy consistency.
Fill a piping bag with the banana pudding mixture and pipe a small amount into the cups. If you do not have a piping bag, simply spoon the mixture into the cups.
Add a banana slice to each cup on top of the banana pudding. Pipe a layer of the remaining banana pudding mixture on top of the bananas until it fills the cups about 3/4 full.
To make the whipped cream, use the electric hand mixer to whip heavy cream, powdered sugar, and vanilla extract until still peaks form.
Pipe a dollop of whipped cream on top of each dessert cup and sprinkle on additional vanilla wafer crumbs.
Seal the cups with a lid and chill. The cups can be served immediately or stored in the refrigerator for 2-3 days. I actually think they taste best after a few days!