In a bowl, combine the butter at room temperature, the eggs and the powdered sugar and work them by hand until the mixture becomes somewhat uniform. Add the vanilla and flour and continue working. Add the crushed walnuts and shape the dough into circles which we bake for about 20 minutes at 170g. After we take the cookies out of the oven, we dip them in the powdered sugar so that they are completely coated with the latter. Serve after they have cooled.