Gather all ingredients. Preheat the oven to 400 degrees F. Lightly grease a 12-cup muffin tin or line with paper liners.
Combine flour, baking powder, sugar, and salt in a large bowl.
Stir in milk, egg, butter, and chocolate chips until combined.
Pour batter into the prepared muffin cups. You will get 12 (maybe 13-14) regular sized muffins if you fill the cups nearly to the top.
Bake at 400F for 5 min and then without opening the oven door, decrease temp to 350 until a toothpick inserted into the center of a muffin comes out clean, 15 to 20 additional minutes.
For Mini Muffins
Follow steps 1-3 above.
Fill greased or lined mini muffin cups very full to get about 2 dozen mini muffins.
Bake at 400F for 5 min and then without opening the oven door, decrease temp to 350 until a toothpick inserted into the center of a muffin comes out clean, about 10 to 15 additional minutes. Watch closely though, as baking times may vary.
