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 until the mixture resembles fine crumbs.

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 9-inch 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. Keep the oven temperature at 325°F (163°C).

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

In a stand mixer or large mixing bowl, 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 vanilla extract, mixing until well combined.

In a separate bowl, lightly beat the eggs. Add to the cheesecake filling and mix on low speed until just combined. Use a rubber spatula to mix thoroughly.

Secure the springform pan with aluminum foil to prevent water from entering while baking. Place it in an oven bag, rolling the sides down.

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

Add boiling water to a roasting pan until it is about 1-inch deep. Place the springform pan inside.

Transfer to the oven and bake for 70 to 80 minutes or until the edges are set and the center is slightly jiggly. Turn off the oven, crack the door, and let it cool in the warm oven for 1 hour.

After cooling, transfer to a wire rack to cool completely. Cover tightly and chill in the refrigerator for 5 to 6 hours or overnight.

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

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