Preheat oven to 375°F.
Liberally grease or spray with nonstick spray a one pound loaf pan and set aside.
In a mixing bowl, combine the flour, baking powder, salt, and the zest of one lemon, reserving the juice.
In another small bowl cream together the butter and sugar until smooth, then add eggs one at a time, then stir in the milk, vanilla, and reserved lemon juice to create a batter.
Rinse the blueberries and drain, then toss with one tablespoon of flour to coat.
Fold berries into the batter.
Spread batter evenly in the prepared loaf pan and bake for 55-65 minutes.
Cool in pan ten minutes, then turn out and finish cooling on a wire rack.