Put the flour, sugar and salt in a bow, cut the butter into pieces and work it into the flour with your fingertips. Now make a well in the middle of the flour and butter mixture and add the egg, egg yolks and vanilla extract. Stir with a fork to incorporate the flour evenly until you have to begin using your hand. Quickly bring the dry and wet ingredients together with your hands. On a floured surface, knead the dough for a few minutes then roll into ¼-1/2 inch thickness.