Prepare the Crust:

1. Crush the Vanilla Wafers: In a food processor, pulse the vanilla wafers until you have fine crumbs. Alternatively, place them in a plastic bag and crush with a rolling pin.
2. Mix the Crust Ingredients: In a bowl, combine the wafer crumbs, sugar, and melted butter until the mixture resembles wet sand.
3. Press Into a Springform Pan: Press the crust mixture into the bottom of a 9-inch springform pan, making sure it’s evenly distributed and compact. Set aside.

Prepare the Cheesecake Filling:

4. Beat the Cream Cheese: In a large bowl, beat the cream cheese with an electric mixer on medium speed until smooth and creamy.
5. Add Sugar and Eggs: Add the sugar and beat until smooth. Then, add the eggs one at a time, mixing until each is incorporated. Add the vanilla extract and mix again.
6. Add Bananas and Sour Cream: Stir in the mashed bananas and sour cream. Beat until fully combined and smooth.
7. Add Heavy Cream: Finally, pour in the heavy cream and mix until the batter is silky and well combined.

Bake the Cheesecake:

8. Prepare the Oven: Preheat the oven to 325°F (163°C). Place a baking pan with water on the lower rack to create steam while baking the cheesecake, preventing cracking.
9. Bake the Cheesecake: Pour the cheesecake filling into the prepared crust and smooth the top with a spatula. Bake for 1 hour to 1 hour 10 minutes, or until the center is almost set but still slightly wobbly.
10. Cool and Chill: Allow the cheesecake to cool at room temperature for 30 minutes, then transfer it to the refrigerator to chill for at least 3 hours or overnight.

Make the Banana Pudding Layer:

11. Cook the Pudding: In a medium saucepan, whisk together the milk, sugar, egg yolks, and cornstarch. Cook over medium heat, stirring constantly, until the mixture thickens and begins to boil.
12. Add Flavorings: Once thickened, remove from heat and stir in the vanilla extract and butter until smooth. Let the pudding cool slightly before layering it on the cheesecake.
13. Assemble the Layers: Once the cheesecake has cooled and set, spread the banana pudding over the top, then layer the sliced bananas on top of the pudding.

Make the Whipped Cream Topping:

14. Whip the Cream: In a mixing bowl, whip the heavy cream, powdered sugar, and vanilla extract until stiff peaks form.
15. Top the Cheesecake: Spread the whipped cream over the banana pudding layer, smoothing it out evenly. Garnish with additional banana slices and crushed vanilla wafers.