1. Preheat the oven to 350 F. Lightly grease a 9x5-inch loaf pan (1 lb. loaf pan) with cooking spray oil.
2. In a large mixing bowl, combine the dry ingredients including flour, baking powder, sugar, and salt. Whisk together until evenly distributed and set aside.
3. In a medium mixing bowl, whisk well to combine the wet ingredients including milk, oil, egg, vanilla extract, lemon juice, and lemon zest.
4. Pour the wet ingredients into the dry ingredients and mix together using a rubber spatula until just combined and no dry ingredients are visible. Do not overmix (overmixing will make the bread denser and firmer). Fold in 1 cup of blueberries until evenly mixed.
5. Pour the batter into the prepared loaf pan and add the remaining 1/2 cup blueberry on top.
6. Bake for 55 minutes until golden brown and a toothpick inserted into the center of the cake comes out clean. Let cool for 10-15 minutes, then invert to remove the loaf.
7. Serve warm or at room temperature. Drizzle with glaze if desired. 

Lemon Glaze:

1. In a small bowl, add the icing sugar. Slowly add in the lemon juice and continually stir until smooth and desired consistency is achieved. The icing should be thick but can still be poured. If the icing is too runny, add more sugar. If it is too thick, add some more lemon juice.
2. Evenly drizzle glaze over the lemon loaf and allow it to set and dry before slicing the loaf. To completely coat the loaf, then double the amount of icing.