Preheat your oven to 350°F (175°C). Lightly grease a 9×5-inch loaf pan or line with parchment paper for easy removal.
In a medium bowl, whisk together 1 1/2 cups all-purpose flour, baking powder, and salt. Set aside.
In a large bowl, beat melted butter and granulated sugar together until smooth. Add the eggs, one at a time, mixing well after each addition. Stir in vanilla extract, lemon zest, and lemon juice.
Alternate adding the dry ingredients and milk to the wet mixture, beginning and ending with the flour mixture. Stir gently until just combined—don’t overmix!
Toss the blueberries with 1 tablespoon flour to prevent sinking. Fold them gently into the batter.
Pour the batter evenly into the prepared loaf pan. Smooth the top.
Bake for 50–60 minutes, or until a toothpick inserted in the center comes out clean. If the bread is browning too quickly, tent loosely with foil during the last 15 minutes.
Cool the bread in the pan for 10 minutes, then transfer to a wire rack.
For the glaze, whisk together melted butter, powdered sugar, lemon juice, and vanilla extract until smooth. Drizzle over the cooled bread.
Notes
Store in an airtight container for up to 3 days at room temperature. Can be refrigerated for up to 1 week or frozen for up to 3 months.