Preheat the oven to 170°C (338°F).
Combine butter, yellow cheese powder, and sugar in a bowl. Mix until soft and creamy.
Add egg and mix well.
Sift in cake flour, cornstarch, and baking powder, then add to the mixture.
Shape the dough into a ball, wrap in plastic wrap, and let it rest in the refrigerator for 30 minutes.
Take portions of the dough and roll into round shapes.
Place on a baking sheet and bake at 170°C (338°F) for 15 minutes.
Cool completely on a wire rack.