Preheat your oven to 375°F (190°C).
Line a muffin tin with paper liners or grease it lightly.
In a large bowl, whisk together the flour, sugar, baking powder, and salt.
In another bowl, combine the milk, vegetable oil, eggs, and vanilla extract.
Pour the wet ingredients into the dry ingredients and stir until just combined.
Fold in your chosen add-ins (chocolate chips, fruits, etc.).
Fill each muffin cup about 2/3 full with batter.
Bake in the preheated oven for 20-25 minutes, or until a toothpick comes out clean.
Allow the muffins to cool in the pan for 5 minutes, then transfer to a wire rack.
Enjoy your freshly baked muffins warm or at room temperature!