Preheat the oven to 350 degrees F (175 degrees C).
Sift together flour, cinnamon, salt, baking soda, and baking powder. Set aside.
Beat eggs in a large bowl. Add sugar, oil, and vanilla; mix well. Stir in zucchini, then mix in flour mixture until well combined. Stir in nuts. Pour into 2 ungreased loaf pans.
Bake in the preheated oven until a toothpick inserted into the centers of each loaf comes out clean, about 1 hour.