Preheat oven to 350°F (175°C). Line the bottom of a 7-inch springform pan with parchment paper. Set aside.
To make the crust, in a medium bowl, combine crushed vanilla wafers, sugar, and melted butter. Mix until combined. Press the mixture into the bottom of the lined springform pan.
Wrap two pieces of heavy-duty aluminum foil around the bottom and up the sides of the pan to prevent water from getting into the pan during the water bath step.
To the bowl of a stand mixer fitted with the paddle attachment, add the cream cheese. Beat on medium speed until smooth and creamy.
Add the sugar and banana cream pudding mix. Continue to beat until well combined, scraping down the sides of the bowl as needed.
Mix in the mashed banana, sour cream, and vanilla extract until well combined.
With the mixer on low, add the eggs one at a time until fully incorporated, scraping the sides and bottom of the bowl after each addition.
Pour the filling onto the crust.
Using about half of the strawberry mixture, drop spoonfuls onto the cheesecake filling. (Reserve the remaining strawberry mixture in the refrigerator until ready to use for the topping.) Using a knife, gently swirl the strawberry mixture into the cheesecake batter, being careful not to touch the crust, to create a marbled effect.
Place the springform pan into a deep roasting pan. Pour hot water into the roasting pan, about halfway up the side of the springform pan.
Bake for 65-70 minutes, or until the top of the cheesecake turns golden and the edges are set. Remove from the oven and let cool on a wire rack.
Once cooled to room temperature, transfer the cheesecake to the refrigerator to chill for at least 4 hours, up to overnight.
When ready to serve, garnish with whipped cream, the remaining strawberry sauce, fresh strawberries, and sliced bananas.