
Preheat the oven to 400°F. Prepare a muffin pan with paper liners, or grease each muffin cup.
In a large bowl, mix together the flour, sugar, baking powder and salt.
In a separate small bowl, beat the egg, milk and oil. Stir the wet ingredients into the flour mixture just until moistened.
Fold in the chocolate chips. Editor's Tip: Use a spatula or wooden spoon for this step, rather than a hand mixer. This will help to prevent overmixing the batter.
Divide the batter between the 12 prepared muffin cups, filling each three-fourths full. Bake the muffins until a toothpick inserted in one comes out clean, 18 to 20 minutes. Cool the muffins for 5 minutes in the pan before transferring them to a wire rack to finish cooling.