Preheat oven to 350°F (175°C).
Line a 9×5-inch loaf pan with parchment or lightly grease with butter.
In a medium bowl, whisk flour, baking powder, and salt.
In another bowl, mix melted butter, sugar, eggs, vanilla, lemon zest, and lemon juice until smooth.
Alternate adding flour mixture and milk into the wet ingredients, mixing just until combined.
Toss blueberries in 1 tablespoon flour, then gently fold into the batter.
See full steps with tips & photos → https://theboatshedcafe.com/lemon-blueberry-loaf-cake/