Heat oven to 400℉ and prepare the muffin baking pan by adding paper muffin liners. I also recommend spraying the liners with cooking oil spray to help remove the muffins after baking.
Grab a large mixing bowl and whisk together the all-purpose flour, granulated sugar, brown sugar, baking powder, and salt.
Grab a standard measuring cup and pour in ⅓ cup of vegetable oil, the egg, and then pour in skim milk until the mixture reaches the 1 cup line. It should be ~ ½ cup of skim milk. Finally, add the 2 tsp vanilla extract.
Pour the measuring cup mixture into the large mixing bowl with the dry ingredients. Use a fork or large spoon to mix all of the ingredients together. Next, carefully fold in the frozen blueberries.
Add the muffin batter to the prepared muffin cups, fill each one approximately ⅔ full to allow room for expansion during baking.
Bake the muffins 15-20 minutes or until a toothpick inserted into the center of one of the muffins comes out clean.
Carefully remove the muffins from the oven and allow them to cool for 10 minutes.
Enjoy!