1. Preheat the oven to 325°F and grease a 9-inch springform pan. Line the bottom with parchment paper if desired.

2. In a large bowl, mash the bananas until mostly smooth.

3. Stir in the melted butter, brown sugar, 1/4 cup granulated sugar, 2 eggs, 1/4 cup sour cream, and 1 teaspoon vanilla extract until combined.

4. In a separate bowl, whisk together the flour, baking soda, salt, and cinnamon.

5. Fold the dry ingredients into the banana mixture just until combined, then stir in 1/2 cup chopped walnuts.

6. Spread the banana bread batter evenly into the prepared pan.

7. In another bowl, beat the softened cream cheese until smooth.

8. Add 3/4 cup granulated sugar and mix until creamy.

9. Beat in 2 eggs, 1/4 cup sour cream, and 1 teaspoon vanilla extract until the cheesecake filling is smooth.

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

11. Bake for 55 to 70 minutes, or until the center is mostly set with a slight jiggle.

12. Cool at room temperature for 1 hour, then refrigerate for at least 6 hours or overnight.

13. Whip the heavy whipping cream with powdered sugar until soft peaks form.

14. Spread or pipe the whipped cream over the chilled cheesecake.

15. Finish with the remaining chopped walnuts before slicing and serving.