Preheat the oven to 350°F. Line a 9-inch loaf pan with parchment paper leaving an overhang on the two longer sides. Grease the parchment paper with cooking spray.
In a large bowl, whisk together the flour, sugar, brown sugar, baking soda and salt.
In a separate medium bowl, whisk together the mashed bananas, sour cream, eggs, vegetable oil and vanilla extract. Add the wet ingredients to the dry ingredients, mixing just until combined. Stir in chocolate chunks, then scrape the batter into the prepared loaf pan.
Bake the bread for 50 to 60 minutes or until a toothpick inserted comes out clean. Remove the bread from the oven and allow it to cool in the pan for 10 minutes before using the parchment paper overhangs to lift the loaf out of the pan and onto a rack to cool completely.
★ Did you make this recipe? Don't forget to give it a star rating below!