1) Preheat oven to 350 degrees F. Grease 1 regular loaf pan and 1 mini loaf pan, or use a cake pan. Double the recipe and use 3 loaf pans.
2) Stir together the flour, baking powder, and salt in a bowl. In another bowl, whisk or use an electric mixer to mix together the yogurt, 1 cup maple syrup, eggs, lemon zest, and vanilla. Slowly whisk the dry ingredients into the wet ingredients. With a rubber spatula, fold the oil into the batter. Gently fold in blueberries. (If using frozen blueberries, I add the blueberries to batter after the batter is in the pans so the batter doesn't turn purple.) Pour the batter into prepared bread pans (about 1/2 full) and bake for about an hour or until a toothpick comes out clean.
3) Meanwhile, make lemon syrup by microwaving 1/4 cup lemon juice mixed with 2 tablespoons maple syrup in a microwave safe bowl until dissolved.
4) When bread is done, while still warm, poke several holes everywhere in the bread with a toothpick. Pour lemon sugar mixture over bread and allow to soak in and cool completely before taking bread out of loaf pan.