Preheat oven to 350 degrees F. Grease 2 loaf pans. In large bowl, combine flour, cinnamon, baking soda, baking powder and salt; mix well. Set aside. In medium bowl, combine sugar and eggs; beat until well blended. Add oil and vanilla; beat until combined. Stir in zucchini. Add flour mixture; stir just until moistened. Stir in nuts.
Divide and spoon batter evenly into loaf pans.
Bake 55 to 60 minutes or until toothpick inserted in center comes out clean. Cool in pans 10 minutes. Remove breads from pans; cool completely on wire racks.