Prepare the Crust: Preheat oven to 325°F (160°C). Line a 12-cup muffin tin with paper liners. In a bowl, mix crushed vanilla wafers, sugar, and melted butter until combined. Press about 1–2 tablespoons of the mixture into each liner to form a base. Bake for 5 minutes, then set aside to cool slightly.

Make the Cheesecake Batter: In a large mixing bowl, beat cream cheese and sugar until smooth. Add eggs one at a time, mixing well after each addition. Stir in vanilla extract, sour cream, and mashed bananas until creamy.

Assemble: Divide the batter evenly among the muffin cups, filling each nearly to the top.

Bake: Bake for 18–22 minutes, or until the centers are just set but still slightly wobbly. Turn off oven, crack the door, and let cheesecakes cool inside for 10 minutes to prevent cracking. Remove and cool completely at room temperature, then refrigerate for at least 2 hours.

Whipped Cream Topping: Beat heavy cream, powdered sugar, and vanilla until stiff peaks form. Pipe or spoon over chilled cheesecakes.

Garnish and Serve: Top with a banana slice and sprinkle crushed vanilla wafers before serving.