Stir flour, cinnamon, ginger, allspice, nutmeg, and walnuts together. In a separate bowl, blend oil, honey, eggs, and vanilla. Add wet ingredients to dry ingredients. Mix only until moistened. Gently fold in grated apple. Pour batter into an oiled 9x5 loaf pan. Bake at 325 degrees for 50 to 60 minutes or until toothpick inserted in center comes out clean.