Preheat oven to 400F. Spray a Non-Stick 12-Cup Regular Muffin Pan very well with floured cooking spray or grease and flour the pan; set aside. (I don’t prefer the cosmetic look of muffin liners). Note – I only used 10 cavities rather than all 12.
To a large bowl, add the egg, sugar, milk, oil, vanilla, and whisk until combined.
Add the flour, baking powder, salt, and stir until just combined; don’t overmix.
Add the chocolate chips and stir to combine.
Divide batter equally among 10 cavities of the prepared pan. Each cavity will be about 3/4 full; don’t fill past 3/4 full. Spraying a one-quarter cup measure with cooking spray so the batter slides right off is handy here.
If desired, evenly sprinkle a generous pinch of chocolate chips to the top of each muffin.
Bake for about 10 to 12 minutes, or until tops are set and a toothpick inserted in the center comes out clean, or with a few moist crumbs but no batter. All muffin pan sizes, how full you fill your pan, ovens, climates, etc. vary so bake until done given your variables and check on them early.
Allow muffins to cool in pan for about 10 minutes before removing and placing on a rack to cool completely.
Notes
Muffins will keep airtight at room temperature for up to 5 days, or in the freezer for up to 6 months.