In a large mixing bowl, beat the egg yolks with the granulated sugar until smooth using an eggbeater or an electric mixer. Add 1 cup of the flour and the milk, butter, and lemon zest and mix well. Put the mixture in a saucepan and warm it over low heat until it becomes as thick as mashed potatoes. Spread the mixture out onto a buttered cookie sheet with a spatula and let it cool for at least 30 minutes. When it has set, cut the sheet into 1 1/2 by 2-inch diamond shapes with a sharp knife greased with vegetable oil.
In a mixing bowl, beat the whole eggs. Dip the diamond shapes first in the remaining flour, then in the eggs, then into the bread crumbs. Fill a pan 3 inches deep with vegetable oil. Heat the oil over medium-high heat. When it is 375 degrees F. (a drop of water will sizzle and splatter), slide the diamonds in and fry them until they are golden, 3 to 4 minutes. Remove from the oil with a slotted spoon and let them drain on paper towels. Sprinkle lightly with confectioners' sugar and serve.
Recipe courtesy of Pino Luongo, Simply Tuscan. Published by Doubleday, 2000.