Preheat the oven to 325°F (163°C).

Line the bottom of a 9-inch springform pan with parchment paper. Set aside.

Crush the Nilla wafers in a food processor or blender until the mixture resembles fine crumbs.

Combine the crushed Nilla wafer crumbs and granulated sugar in a mixing bowl and stir until well combined. Add melted butter and mix until all crumbs are moistened.

Scoop the mixture into the prepared pan and press down into an even layer.

Bake for 10 minutes, then remove and set aside to cool while preparing the filling.

Place a pot of water on the stove to boil for the water bath.

Beat the cream cheese on low-medium speed until smooth, approximately 1 to 2 minutes.

Add mashed banana and sour cream, mixing until fully combined. Then add sugar, pudding mix, and vanilla extract and mix well.

In a separate bowl, lightly beat the eggs and add to the mixture, mixing on low speed until just combined.

Wrap the bottom of the springform pan in aluminum foil to prevent water from entering.

Pour cheesecake filling into the springform pan, smoothing out to an even layer.

Add boiling water to a roasting pan until about 1-inch deep, and place the wrapped springform pan in the roasting pan.

Bake in the oven for 70 to 80 minutes or until edges are set and the center is slightly jiggly.

Allow cheesecake to cool in the oven for 1 hour, then transfer to a wire rack to cool completely before refrigerating for 5 to 6 hours or overnight.

Run a thin knife around the edge of the cheesecake to loosen from the pan and release the springform.

Decorate with whipped cream, sliced bananas, and Nilla wafers.