Preheat oven to 375°F (190°C).

Line a muffin tin with parchment paper or muffin liners.

In a large mixing bowl, whisk together the flour, sugar, baking powder, salt, and cinnamon.

In another bowl, whisk milk, vegetable oil, eggs, and vanilla extract until smooth.

Add the wet mixture to the dry ingredients and stir until just combined.

Gently fold in the blueberries with a rubber spatula.

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

Bake for 20-25 minutes, or until a toothpick inserted into the center comes out clean.

Let muffins cool in the pan for a few minutes before transferring to a wire rack.