This moist, tender banana bread is studded with juicy blueberries and warmed with a hint of cinnamon. It comes together in minutes and bakes up with a golden crust and soft crumb—perfect for breakfast, snacking, or dessert.
Preheat oven to 350°F. Grease a 9x5-inch loaf pan and line with a parchment sling.
Toss the blueberries with 1 tablespoon flour until evenly coated; set aside.
In a medium bowl, whisk together 1.5 cups flour, baking soda, baking powder, salt, and cinnamon.
In a large bowl, whisk melted butter with granulated sugar and brown sugar until glossy. Whisk in mashed bananas, eggs, vanilla, and sour cream until smooth.
Add dry ingredients to the wet ingredients and fold gently just until a few streaks of flour remain.
Fold in lemon zest (if using) and the floured blueberries until just combined—do not overmix.
Scrape batter into the prepared pan and smooth the top. Tap the pan lightly to release air bubbles.
Bake 55 to 65 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs. Tent with foil after 45 minutes if the top is browning too quickly.
Cool in the pan for 15 minutes, then lift out to a wire rack to cool completely.
Slice into 10 pieces and serve plain or with a pat of butter.
Notes
For best texture, use very ripe bananas with plenty of brown spots. Bread keeps at room temperature for 3 days wrapped, or freeze slices for up to 2 months. If using frozen blueberries, do not thaw—toss with flour and bake, adding 5 minutes if needed.