Prepare the Crust:

1. Preheat your oven to 325°F (163°C) and line a muffin tin with paper liners or grease a mini cheesecake pan.
2. In a bowl, combine the graham cracker crumbs, sugar, and melted butter until the mixture resembles wet sand.
3. Press about 1-2 tablespoons of the mixture into the bottom of each muffin cup to form the crust.
4. Bake the crusts for 5 minutes, then remove from the oven and set aside to cool.

Make the Cheesecake Filling:

1. In a large mixing bowl, beat the softened cream cheese and sugar until smooth and creamy.
2. Add the eggs, one at a time, beating well after each addition.
3. Mix in the vanilla extract and sour cream, and finally fold in the mashed banana until well combined.
4. Spoon the cheesecake filling over the cooled crusts, filling each about ¾ full.

Bake the Mini Cheesecakes:

1. Bake the mini cheesecakes for 18-20 minutes, or until the centers are set but still slightly jiggly.
2. Turn off the oven and leave the cheesecakes inside with the door slightly open to cool gradually, about 10-15 minutes. Then remove them and let them cool completely.
3. Refrigerate the cheesecakes for at least 4 hours or overnight to set fully.

Add the Banana Topping:

1. Before serving, toss the banana slices in lemon juice to prevent browning.
2. Top each mini cheesecake with a dollop of whipped cream (optional) and banana slices.
3. Drizzle with caramel sauce or white chocolate sauce for extra indulgence.