01 - Preheat oven to 400°F. Line a 12-cup muffin tin with paper liners or grease thoroughly with cooking spray.
02 - In a large mixing bowl, whisk together flour, sugar, baking powder, baking soda, and salt until evenly distributed.
03 - In a separate bowl, whisk eggs, oil or melted butter, yogurt or buttermilk, lemon zest, lemon juice, and vanilla extract until smooth and well combined.
04 - Pour wet ingredients into dry ingredients. Gently fold together using a spatula just until combined. Do not overmix—some small lumps are acceptable.
05 - Toss blueberries with 1 tablespoon flour in a small bowl to coat. Gently fold coated berries into the batter.
06 - Divide batter evenly among the 12 muffin cups. Sprinkle tops with coarse sugar if desired.
07 - Bake for 18 to 22 minutes until golden brown and a toothpick inserted into the center of a muffin comes out clean.
08 - Let muffins cool in the tin for 5 minutes. Transfer to a wire rack and cool completely before serving.