Preheat the oven to 180°C (356°F).
Sift cake flour, baking powder, and cocoa powder into a bowl.
In a separate bowl, add eggs and sugar and mix well.
Add the dry ingredients and chocolate chips to form a dough.
Shape the dough into a log and place it on a baking tray.
Bake in the preheated oven at 180°C (356°F) for 20–25 minutes.
Remove and let cool, then slice into pieces about 1.5cm thick.
Place the slices back on the tray and bake at 150°C (302°F) for another 10–15 minutes.