Prep your pan and oven. Heat oven to 350°F (175°C). Line a 9x5-inch loaf pan with parchment, leaving overhang for easy lifting. Lightly grease the pan and parchment.

Mash the bananas. In a large bowl, mash the bananas until mostly smooth with a few small lumps. You should have about 1 1/3 to 1 1/2 cups.

Whisk in the wet ingredients. Add granulated sugar, brown sugar, melted butter, eggs, yogurt, vanilla, lemon zest, and lemon juice. Whisk until well combined and glossy.

Mix the dry ingredients separately. In another bowl, whisk flour, baking soda, baking powder, and salt. This prevents clumps and ensures even rise.

Combine gently. Add the dry mixture to the wet. Stir with a spatula just until you don’t see dry streaks. Do not overmix or the loaf can turn dense.

Prep the blueberries. Toss blueberries with 1 teaspoon of flour to help keep them from sinking. Fold them into the batter gently so they don’t burst.

Fill the pan. Scrape the batter into the prepared pan and smooth the top. Sprinkle with coarse sugar if you like a crackly finish.

Bake. Bake 55–70 minutes, until the top is deep golden and a tester comes out clean or with a few moist crumbs. If the top browns too fast, tent loosely with foil for the last 15 minutes.

Cool properly. Let the loaf cool in the pan for 15 minutes. Use the parchment to lift it to a rack. Cool at least 1 hour before slicing so it sets and stays moist.

Optional glaze. Whisk powdered sugar and lemon juice until smooth and drizzle over the cooled loaf for extra zing.