Preheat the oven to 400 degrees F, and place cupcake liners in 8 muffin cups or grease the muffins cups well.
Place the butter, milk, egg, and vanilla in a medium bowl, and beat with a fork for 30 seconds or until the mixture is well combined.
Combine the flour, the sugars, baking powder, and salt in a large bowl. Make a well in the center of the dry ingredients, and pour in the wet ingredients. Stir until just combined, and then gently mix in the chocolate chips being careful not to over mix.
Spoon the mixture into the prepared muffin cups. A large ice cream scoop is a mess-free way to evenly portion out the batter.
Bake on the middle rack of the oven for 14-16 minutes or until the muffins are starting to brown and pass the toothpick test. They will feel slightly firm to the touch.
Remove from the oven, cool in the pan for a few minutes, and then remove to a rack to cool completely. Enjoy warm or at room temperature.