Preheat the oven to 325°F (163°C). Line the bottom of a 9-inch springform pan with parchment paper and set aside.

Crush the Nilla wafers in a food processor or blender until the mixture resembles fine crumbs. Alternatively, crush them in a sealed ziplock bag with a rolling pin.

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

Scoop the mixture into the prepared springform pan and firmly press it down into one even layer. Bake for 10 minutes, then remove from the oven and set aside to cool while you make the filling.

Place a large pot of water on the stove to boil for the water bath before getting started with the filling.

In the bowl of a stand mixer fitted with the paddle attachment, or in a large mixing bowl using a handheld mixer, beat the cream cheese on low-medium speed until smooth (about 1 to 2 minutes).

Add the mashed banana and sour cream, mixing until fully combined. Then, add the granulated sugar, banana cream pudding mix, and pure vanilla extract and mix until well combined (about 30 to 60 seconds).

In a separate small mixing bowl, lightly beat the eggs. Add the beaten eggs to the mixing bowl with the cheesecake filling and mix on low speed until just combined. Use a rubber spatula to ensure everything is fully mixed together.

Secure the bottom of the springform pan with 2 to 3 layers of aluminum foil to prevent water from entering the pan while baking. Place the wrapped springform pan in an oven bag and roll the sides down.

Pour the cheesecake filling into the springform pan and smooth it out into one even layer.

Add the boiling water to a large roasting pan until it is about 1-inch deep. Carefully place the wrapped springform pan into the roasting pan.

Transfer the roasting pan with the cheesecake to the oven and bake for 70 to 80 minutes or until the edges of the cheesecake are set and the center is still slightly jiggly.

Turn the oven off, crack the oven door slightly, and allow the cheesecake to cool in the warm oven for 1 hour.

After the cheesecake has cooled for 1 hour, remove it from the oven and transfer it to a wire rack to cool completely.

Once cooled, cover tightly and transfer to the refrigerator to chill for 5 to 6 hours or overnight.

Once the cheesecake is completely cooled and chilled, run a thin knife around the outside of the cheesecake to loosen it from the pan. Carefully release the springform pan.

Decorate the cheesecake with a generous amount of whipped cream, sliced bananas, and Nilla wafers.