Preheat oven to 400 degrees. Grease or line 12 cup muffins tins.
In a large bowl ad flour, sugar, baking powder and salt, Whisk together.
Using a liquid 1 cup measuring cup, measure vegetable oil. Then add an egg to the cup followed by enough milk to reach the one cup measure. Add vanilla and whisk with a fork until combined.
Add milk mixture to the flour mixture then use a fork to combine. Do not over mix. The batter will be thick. Add blueberries and fold in with a spatula.
Divide the batter evenly between the muffin cups.
Bake at 400 degrees for 15-20 minutes until toothpick inserted in a center of a muffin. When it comes out clean the muffins are done. Makes 12 muffins.