Preheat your oven to 350℉ (175℃) and prepare a 12-cup muffin tin with paper liners.

In a large bowl, whisk together the flour, cocoa powder, sugar, baking powder, and salt, along with the chocolate chips, reserving a few chocolate chips for topping the muffins (optional).

Into a large liquid measuring cup or bowl, add the milk, eggs, vanilla and oil. Whisk together with a fork.

Add the liquid ingredients and mix everything together just until no streaks of flour remain.

Divide the batter evenly between the 12 muffin cups and top with the remaining chocolate chips (optional).

Bake at 350℉ (175℃) for about 23-25 minutes, or until a toothpick inserted into the center of one of the muffins comes out clean.