Preheat your oven to 400°F (200°C) and line a 12-cup muffin tin with paper liners or grease it well.

In a large bowl, whisk together the dry ingredients: flour, sugar, baking powder, and salt.

In a separate medium bowl, whisk together the wet ingredients: egg, milk, vegetable oil, and vanilla extract.

Pour the wet ingredients into the dry ingredients and mix until just combined; be careful not to overmix, as lumps are okay.

Gently fold in the fresh blueberries until evenly distributed throughout the batter.

Divide the batter evenly among the 12 muffin cups, filling each about two-thirds full.

Bake for 18-22 minutes, or until the tops are golden brown and a toothpick inserted into a muffin comes out clean.

Let the muffins cool in the tin for a few minutes before transferring them to a wire rack to cool completely.