Preheat your oven to 325°F (163°C). In a food processor, blend Nilla Wafers into fine crumbs, then mix with brown sugar and melted unsalted butter until well combined. Press this mixture firmly into the bottom of a springform pan to form an even layer. Bake for about 11 minutes until lightly golden, then set aside to cool completely.

In a large mixing bowl, beat the room-temperature cream cheese and granulated sugar until smooth and creamy. Add the mashed bananas, vanilla extract, sour cream, and heavy cream, mixing until well incorporated. Add the eggs one at a time, beating just until combined.

Pour half of the cheesecake filling into the cooled crust. Layer with sliced bananas and a sprinkle of crushed Nilla Wafers. Pour the remaining filling over the top and smooth it out.

Prepare a water bath and bake in the preheated oven for 80-90 minutes, until the edges are set with a slight jiggle in the center. Chill for at least 6 hours, preferably overnight.

Whisk the instant pudding mix with cold milk until thickened. Whip the heavy cream until stiff peaks form, and fold it into the pudding mixture.

Spread the pudding topping over the chilled cheesecake. Sprinkle crushed Nilla Wafers on top and serve chilled.