Preheat your oven to 325°F (163°C). In a food processor, pulse Nilla Wafers until you achieve fine crumbs, then combine them with melted unsalted butter and brown sugar until the mixture resembles wet sand. Press this mixture firmly into the bottom of a springform pan, ensuring it's even. Bake for 11 minutes or until lightly golden, then set aside to cool.

In a large mixing bowl, beat the cream cheese and granulated sugar together until smooth and creamy—about 2 minutes. Gradually add in the mashed bananas, pure vanilla extract, sour cream, and heavy cream, mixing until fully combined. Once smooth, add the large eggs one at a time at low speed, mixing just until incorporated to maintain a light texture.

Pour half of the cheesecake filling over the cooled Nilla Wafer crust, spreading evenly. Arrange sliced bananas evenly on top, followed by a sprinkle of crushed Nilla Wafers for added texture. Finally, pour the remaining cheesecake batter over the layered bananas and crumbs, ensuring everything is covered smoothly.

Prepare a water bath to bake the cheesecake evenly and prevent cracking. Place your springform pan in a larger pan filled with hot water, making sure the water comes halfway up the sides of the cheesecake pan. Bake in the preheated oven for 80-90 minutes, or until the edges are set but the center still slightly jiggles. Turn off the oven and leave the cheesecake inside for 30 minutes to cool gradually.

After cooling in the oven, carefully remove the cheesecake from the water bath and let it cool to room temperature. Once cooled, wrap it with plastic wrap and refrigerate for a minimum of 6 hours, or preferably overnight, to allow the flavors to meld beautifully.

In a mixing bowl, whisk together the instant vanilla pudding mix and milk until thickened, about 2 minutes. In another bowl, whip the heavy cream until stiff peaks form. Gently fold the whipped cream into the pudding mixture, being careful to keep the volume intact.

Once the cheesecake has chilled completely, spread the whipped pudding mixture evenly over the top. Finish by sprinkling crushed Nilla Wafers on top for a beautiful presentation.