Place the flour on a flat, clean surface and make a hole in the center.
Place the icing sugar, butter, eggs, salt, vanilla and lemon zest in the center of the hole.
Mix directly with your hands, from the inside out, until all the ingredients are well integrated. SEE THE VIDEO
Sprinkle a little flour on the surface and start kneading the dough as shown in the video, until you get a smooth dough that does not stick to your fingers.
Cover the dough with clear paper and let it sit in the fridge for about 30 minutes before using it.
