Mix everything together and bake in the air fryer at 180°C for 20 minutes.
Combine cake flour, cocoa powder, sugar, baking powder, and salt in a bowl.
Add cold butter and cut it into the flour mixture until crumbly.
Add egg and milk, and bring the dough together into a lump.
Quickly mix in the chocolate chips.
Shape the dough into a round and cut into 6 equal pieces.
Bake in a preheated oven at 180°C for 20-25 minutes.