Preheat oven to 400°F. Combine flour, baking powder, baking soda, and salt in a bowl, then set aside.
In a separate large bowl, whisk together the melted butter and sugars. Then whisk in the milk, eggs, and vanilla extract until well combined.
Gently fold in the dry ingredients until just combined, being careful not to overmix—a few lumps are just right! Then fold in the chocolate chips.
Line your 12-cup muffin tin with liners or grease well. Fill each cup most of the way full, then bake in preheated oven for 5 minutes.
After five minutes, turn down the oven temperature to 350°F and bake for another 14-17 minutes. A toothpick inserted into the center of a muffin should come out clean.
Allow the muffins to cool, then serve or store in an airtight container.
Notes
These keep well in an airtight container for up to 3 days or in the freezer for up to 3 months.
To get that bakery-style dome on your muffins, make sure to fully melt the butter before mixing it with the sugars. If it's not completely melted, the muffins can turn out flat. They'll still be delicious, though!