Preheat the oven to 350 degrees F. Lightly grease two 4 1/2 by 8 1/2 -inch loaf pans. In a medium-sized bowl, combine the flour, cinnamon, baking powder, baking soda and salt. Mix well and set aside. Beat together the apple sauce and sugar in a large mixing bowl. Beat in the eggs one at a time. Stir in the zucchini, walnuts and vanilla. Add the dry ingredients and stir until just combined. Divide the batter between the prepared loaf pans. Bake one 1 hour, or until a toothpick inserted in the centre comes out clean. Cool the loaves in their pans 10 minutes. Unmould and cool to room temperature. Loaves freeze well.