Sift the cake flour, cocoa powder, and baking powder together.
In a bowl, add the egg and sugar and mix with a whisk.
Add milk and melted butter to the egg mixture and stir to combine.
Add the dry ingredients and mix well to form a dough.
Gently fold in the chocolate chips.
Shape the dough into balls and place them on a baking tray.
Bake in a preheated oven at 180°C (356°F) for 15–18 minutes.