Preheat oven to 375°F (190°C). Line a 12-cup muffin tin with paper liners.
In a large bowl, whisk together flour, sugar, cocoa powder, baking powder, baking soda, and salt.
In a separate bowl, whisk together eggs, oil, milk, and vanilla extract.
Pour wet ingredients into dry ingredients and gently fold until just combined.
Gently fold in chocolate chips.
Fill each muffin liner about 2/3 full.
Bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean.
Let the muffins cool in the tin for a few minutes before transferring them to a wire rack to cool completely.