Preheat the oven to 180°C (356°F).
In a bowl, combine eggs and sugar and mix well.
Add milk and cooking oil, stirring thoroughly.
Sift in cake flour, cocoa powder, and baking powder, then mix until well combined.
Add chocolate chips and gently fold them in.
Divide the batter evenly into muffin cups.
Bake in the preheated oven for 20 minutes.