Preheat the oven to 180°C (356°F).
Combine cake flour, cocoa powder, baking powder, and salt in a bowl.
Add butter and sugar and cream together.
Add the egg and mix well.
Add the prepared dry ingredients and gently mix.
Spread the dough evenly onto a baking pan.
Sprinkle chocolate chips on top.
Bake in the oven for 20 minutes.
Cool and cut into bite-sized pieces.