Preheat oven to 350°F (175°C) and line a muffin tin with paper liners.
In a large mixing bowl, whisk together flour, cocoa powder, baking powder, baking soda, and salt.
In a separate bowl, beat eggs with sugar until light and fluffy. Add milk, oil, and vanilla extract; whisk until smooth.
Gently fold the wet ingredients into the dry mixture. Stir just until combined, do not overmix.
Fold in chocolate chips, ensuring they are evenly distributed in the batter.
Spoon the batter into muffin cups, filling each about ¾ full.
Sprinkle extra chocolate chips on top for a richer finish.
Bake for 18–20 minutes, or until a toothpick inserted into the center comes out clean.
Let muffins rest in the tin for 10 minutes, then transfer to a wire rack to cool completely.