Preheat your oven to 350°F (177 °C). Line a Loaf Pan (8.5 x 4.5) with parchment paper or lightly grease it (9X5 will work too). Rinse and drain the berries, then toss them with 1 tablespoon of flour in a small bowl. (discard any excess flour at the bottom of the bowl). Set Aside.
In a large mixing bowl whisk together the flour, baking powder, and salt. Set aside.
In a medium bowl, add the soy milk, oil, sugar, lemon juice, zest, and vanilla. Whisk to combine well.
Now slowly pour the wet ingredients into the large bowl of dry ingredients. Using a spatula, stir and fold the batter gently until just combined (don’t overmix - some small lumps are fine). The batter should be thick.
Fold in the blueberries being careful not to overmix the batter.
Scrape the batter out of the bowl with a rubber spatula then gently spread it out evenly. Place on the center rack in your oven. Bake for 55-65 minutes or until a toothpick comes out clean (check in 3 places). Small crumbs are ok, just not wet batter.
Remove from oven and let the loaf cool for 10-15 minutes before transferring it to a cooling rack. Let the loaf completely cool before glazing.
To make the glaze, whisk the powdered sugar and lemon juice together until fully combined and smooth. Drizzle over the cooled loaf.