Preheat oven to 350°F. Coat a 12-cup muffin cup with baking spray.
Whisk ¾ cup each all-purpose flour and whole-wheat flour, ½ cup oats, 1 teaspoon each baking powder and baking soda and ½ teaspoon salt together in a medium bowl.
In another medium bowl, whisk ⅔ cup milk, ⅓ cup oil, ¼ cup honey, 1 tablespoon lemon zest, ¼ cup lemon juice, 1 egg and 2 teaspoons vanilla until well combined.
Make a well in the center of the flour mixture. Add the milk mixture; stir until no dry streaks remain (it’s OK if the batter is slightly lumpy). Gently fold in 1¼ cups blueberries until combined.
Spoon the batter into the prepared muffin cups (about ¼ cup each); sprinkle the tops with 1 tablespoon turbinado sugar and the remaining ¼ cup blueberries.
Bake until golden brown and a wooden pick inserted in the center comes out with a few moist crumbs, 16 to 18 minutes.
Let cool on a wire rack for 5 minutes; serve warm.
