Preheat your oven to 325°F (163°C). Grease a 9-inch springform pan.
In a bowl, mix crushed vanilla wafers with melted butter. Press into the bottom of the pan to form the crust.
In a large mixing bowl, beat the cream cheese and sugar until smooth.
Add sour cream, mashed bananas, eggs, flour, and vanilla extract. Mix until combined.
Pour the cheesecake batter over the crust and smooth the top.
Bake for 55–60 minutes until the center is set. Let cool completely.
In another bowl, whisk together banana pudding mix with cold milk. Chill until thickened.
Spread the pudding evenly over the cooled cheesecake.
Top with whipped cream and garnish with extra banana slices or crushed wafers if you like.
Chill in the fridge for at least 4 hours or overnight before serving.