1. Preheat the oven to 325°F (163°C). Grease a 9-inch springform pan, line the bottom with parchment, and if using a water bath, wrap the outside of the pan tightly in a double layer of heavy-duty foil.

2. In a medium bowl, combine the graham cracker crumbs, vanilla wafer crumbs, granulated sugar, melted butter, and kosher salt until the mixture resembles wet sand. Press firmly into the bottom of the prepared pan in an even layer. Bake for 10 minutes, then set aside to cool slightly.

3. In a large mixing bowl, beat the softened cream cheese and granulated sugar together until completely smooth and fluffy, scraping down the sides of the bowl as needed. Add the cornstarch and kosher salt and mix until combined.

4. Add the eggs one at a time, mixing on low speed just until each egg is incorporated. Stir in the vanilla extract, sour cream, and heavy cream until the batter is velvety and smooth.

5. In a separate small bowl, mash the ripe bananas with the lemon juice until mostly smooth. Gently fold the mashed bananas into the cheesecake batter, taking care not to overmix so you don’t whip in too much air.

6. Pour the banana cheesecake filling over the pre-baked crust and smooth the top with a spatula. Tap the pan a few times on the counter to release any large air bubbles. Place the pan on the middle oven rack, or in a larger roasting pan with hot water for a water bath if desired.

7. Bake for 50 to 60 minutes, until the edges are set and the center still has a slight wobble. Turn off the oven, crack the door, and let the cheesecake sit inside for 30 minutes to cool gradually.

8. Remove the cheesecake from the oven, run a thin knife around the inside edge of the pan to loosen it, and let it cool completely on a wire rack. Cover and refrigerate for at least 4 hours or overnight until fully chilled and set.

9. When ready to top, whisk the instant banana cream pudding mix with the cold milk in a medium bowl for about 2 minutes, until thickened. In a separate bowl, whip the cold heavy whipping cream, powdered sugar, and vanilla extract to soft peaks. Fold about half of the whipped cream into the banana pudding to create a light, fluffy topping.

10. Release the chilled cheesecake from the springform pan and transfer it to a serving plate. Spread the banana pudding mixture over the top in an even layer. Pipe or spoon the remaining whipped cream around the edge of the cheesecake.

11. Arrange the sliced bananas over the top, sprinkle with crushed vanilla wafers, and drizzle generously with warm caramel sauce. Add rainbow sprinkles if you like. Slice with a warm, sharp knife and serve chilled.