Preheat your oven to 375°F (190°C).
Line a muffin tin with paper liners or grease it.
In a large bowl, whisk together flour, sugar, salt, and baking powder.
In another bowl, combine milk, vegetable oil, egg, and vanilla extract.
Pour wet ingredients into dry ingredients and stir until just combined.
Gently fold in the blueberries.
Divide the batter among the muffin cups, filling each about 2/3 full.
Bake for 20-25 minutes, or until a toothpick comes out clean.
Allow to cool in the tin for 5 minutes, then transfer to a wire rack.