Preheat oven to 350° F (175° C). Grease and flour an 8 ½ x 4 ½ inch loaf pan.
Mix flour, sugar, baking powder, and salt in a large bowl. Stir milk, oil, egg, and vanilla extract into flour mixture until batter is just blended.
Combine washed and dried blueberries with 1 tsp of flour and gently fold them into the batter. Pour batter into prepared loaf pan. Sprinkle one tablespoon of sugar over the batter.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, 60 to 70 minutes. Let cool in the pan for 15 minutes, then transfer to a cooling rack and let cool completely.
