Leave the butter at room temperature until it softens.
Add sugar and cream together.
Add the egg yolk and mix well.
Sift in the cake flour and mix with a spatula in a cutting motion.
Form the dough into a ball, wrap it in plastic wrap, and let it rest in the refrigerator for about 30 minutes.
Shape the dough into a cylinder and slice into 0.7cm thick pieces.
Bake in a preheated oven at 180°C for 12–15 minutes.