Preheat the oven to 350 F. Grease and dust with flour two 9x5x3" loaf pans. Wash and dry the zucchini, but do not peel. Cut them into thick slices and grate in the food processor. Set aside. In a large bowl, with an electric mixer at medium speed, beat the eggs until light and frothy. Add the oil, sugar, grated zucchini, and vanilla, beating well. Sift the remaining ingredients together onto a sheet of waxed paper and add to the bowl, mixing well. Pour the batter into the prepared pans, and bake l hour. Cool the loaves in their pans on a wire rack for 30 minutes then turn the loaves out onto the wire rack to cool completely. Wrap the loaves in aluminum foil and refrigerate for several hours for easier slicing, and the loaves may also be frozen.