01 - Preheat oven to 375°F. Line a 12-cup muffin tin with paper liners or grease lightly.
02 - In a large bowl, whisk together flour, cocoa powder, sugar, baking powder, baking soda, and salt.
03 - In a separate bowl, whisk eggs, milk, vegetable oil, and vanilla extract until smooth.
04 - Pour wet ingredients into dry ingredients and gently mix until just combined, avoiding overmixing.
05 - Fold semisweet chocolate chips into the batter evenly.
06 - Divide batter evenly among muffin cups, filling each about three-quarters full.
07 - Bake for 18 to 20 minutes, or until a toothpick inserted in the center comes out with moist crumbs.
08 - Allow muffins to cool in the tin for 5 minutes, then transfer to a wire rack to cool completely.