01 - Preheat oven to 375°F. Line a 12-cup muffin tin with paper liners or grease each cup with butter.
02 - In a large bowl, whisk together all-purpose flour, granulated sugar, baking powder, and salt until thoroughly combined.
03 - In a separate bowl, whisk together vegetable oil or melted butter, egg, milk, Greek yogurt, fresh lemon juice, lemon zest, and vanilla extract until smooth.
04 - Pour the wet mixture into the bowl with the dry ingredients. Gently fold just until combined; the batter will remain slightly lumpy.
05 - Carefully fold in fresh blueberries, mixing as little as possible to avoid breaking the berries.
06 - Divide batter evenly among the muffin cups, filling each about three-quarters full. Bake for 18 to 22 minutes, or until the tops turn golden and a toothpick inserted into the center comes out with a few moist crumbs.
07 - Allow muffins to cool in the pan for 5 minutes before transferring to a wire rack. For the glaze, whisk together powdered sugar, lemon juice and lemon zest until smooth and drizzle over completely cooled muffins if desired.