Preheat your oven to 325°F (165°C) and wrap a 9-inch springform pan in aluminum foil to prevent water from seeping in.

In a mixing bowl, combine crushed vanilla wafer cookies, granulated sugar, and cinnamon. Add melted unsalted butter and mix until resembling wet sand. Press firmly into the bottom of the springform pan and bake for 10 minutes. Allow to cool.

Beat the cream cheese until smooth, gradually add granulated sugar, then eggs one at a time. Fold in vanilla extract, sour cream, pudding mix, and mashed bananas until smooth.

Pour the cheesecake filling into the cooled crust and smooth the top. Place the springform pan inside a larger pan filled with hot water and bake for 60-65 minutes until the center jiggles slightly.

Turn off the oven and leave the door ajar. Cool the cheesecake inside the oven for 1 hour, then cool completely at room temperature.

Combine remaining crushed vanilla wafers with melted butter, brown sugar, and cinnamon. Spread evenly on a baking sheet and bake for 8-10 minutes until golden.

Refrigerate the cheesecake for at least 4 hours, then sprinkle with the crunchy topping and serve.