Preheat oven to 350°F. Spray a 9×5 loaf pan with nonstick spray and set aside.

In a large bowl, whisk together the flour, baking soda, baking powder, salt, and cinnamon. Set aside.

In a large mixer bowl fitted with the whisk attachment, add the butter and brown sugar and beat until light and fluffy, about 4 minutes.

Add eggs one at a time, mixing until just combined.

Add sour cream, mashed bananas, and vanilla extract; mix until combined.

Add dry ingredients and mix just until combined. Do not overmix.

Gently fold in 1 cup (divided) of the chocolate chips.

Pour batter into the prepared pan. Sprinkle remaining ¼ cup of chocolate chips on top.

Bake for 60-65 minutes. Tent with foil after 25-30 minutes if browning too rapidly. Insert a toothpick to check doneness; it should come out clean.

Remove from oven and let cool completely in the pan. Slice and serve.