From the bakery in Greve, in Chianti, Italy. In the bowl of an electric mixer, fitted with a paddle attachment, blend the flour, the sugar, the baking soda and the salt until the mixture is combined well. In a small bowl whisk together the whole eggs, the yolk, the vanilla and the zest, add the mixture to the flour mixture, beating until a dough is formed and stir in the almonds. Turn the dough out onto a lightly floured surface, knead it several times and halve it. Working on a large buttered and floured baking sheet, with floured hands form each piece of dough into a flattish log 12 inches long and 2 inches wide, arrange the logs at least 3 inches apart on the sheet, and brush them with the egg wash. Bake the logs in the middle of a preheated 300F for 50 minutes and them cool on the baking rack for 10 minutes. On a cutting board, cut the logs crosswise on the diagonal into 1/2 inch thick slices, arrange the biscotti, cut sides down, on the baking sheet and bake them, in the 300F oven for 15 minutes on each side. Transfer the biscotti to racks to cool and store them in airtight containers. MAKES: about 48 BISCOTTI SOURCE: Gourmet, December 1992