Preheat oven to 400° F.
Grease a 12-cup muffin tin or line with paper baking cups. Set aside.
In a large bowl, stir together flour, sugar, baking powder, and salt until well blended.
In another bowl or large measuring cup, whisk together eggs, milk, vanilla extract, and melted butter (or vegetable oil).
Pour egg mixture into flour mixture; stir just until moistened.
Stir in chocolate chips; spoon batter evenly into prepared muffin cups.
Bake for 20-25 minutes.
Let muffins cool for a few minutes and serve!