Preheat the Oven:
Preheat the oven to 400°F (200°C).
Line a 12-cup muffin tin with paper liners or grease the cups with a non-stick baking spray.
Mix Dry Ingredients:
In a large mixing bowl, combine 1 1/2 cups of all-purpose flour, 3/4 cup of granulated sugar, 1/2 teaspoon of salt, and 2 teaspoons of baking powder.
Use a whisk to mix these dry ingredients thoroughly until well combined.
Prepare Wet Ingredients:
In a separate medium bowl, beat 1 egg until it is well blended.
Add 1/3 cup of vegetable oil and 1 teaspoon of vanilla extract to the egg. Mix well.
Pour in 1/3 to 1/2 cup of milk gradually, depending on the desired consistency.
Combine Ingredients:
Create a well in the center of the dry ingredients using a spatula.
Pour the wet mixture into the well and stir gently until just combined; do not overmix to avoid dense muffins.
Fold in Blueberries:
Gently fold in 1 cup of blueberries, ensuring they are evenly distributed throughout the batter. If desired, coat the blueberries in a little flour to prevent them from sinking to the bottom.
Fill Muffin Cups:
Use a spoon or ice cream scoop to fill each muffin cup about three-quarters full with batter.
If desired, sprinkle a little sugar on top for a crispy finish.
Bake the Muffins:
Place the muffin tin in the preheated oven.
Bake for approximately 20 to 25 minutes or until a toothpick inserted into the center of a muffin comes out clean.
Cool the Muffins:
Remove the muffin tin from the oven and allow it to cool for 5 minutes.
Transfer the muffins to a wire rack to continue cooling completely before serving.