1. Preheat the oven to 325°F. Grease a 9 inch springform pan and line the bottom with parchment paper.

2. In a medium bowl, whisk together the flour, baking soda, salt, and cinnamon.

3. In a large bowl, whisk together the melted butter, brown sugar, and 1/4 cup of the granulated sugar until smooth.

4. Add the mashed bananas, 1 egg, 1 teaspoon vanilla extract, and 1/4 cup sour cream. Stir until combined.

5. Fold the dry ingredients into the banana mixture just until no dry streaks remain. Spread the batter into the prepared pan.

6. In another bowl, beat the cream cheese until smooth. Add the remaining 1/2 cup granulated sugar and mix until creamy.

7. Beat in the remaining 2 eggs one at a time. Mix in the remaining 1 teaspoon vanilla extract, 1/4 cup sour cream, and cornstarch until smooth.

8. Gently pour the cheesecake filling over the banana bread batter and smooth the top.

9. Bake for 60 to 75 minutes, until the edges are set and the center still has a slight wobble.

10. Turn off the oven, crack the door, and let the cheesecake rest inside for 30 minutes.

11. Remove from the oven and cool completely at room temperature.

12. Chill for at least 6 hours, or overnight, before slicing and serving.