Preheat the oven to 200°C.
In a bowl, combine cake flour, baking powder, sugar, and salt.
Add cold butter and break it up using your hands or a cutter.
Add milk and egg, and knead into one dough ball.
Roll out the dough with a rolling pin to 2cm thickness.
Shape into rounds and cut.
Place onto baking paper.
Brush the surface with milk or beaten egg.
Bake in the preheated oven for 15-20 minutes, then cool.