Preheat oven to 325 degrees F. Grease and line two bread pans.
In a medium bowl, mix flour, salt, baking powder, soda, and cinnamon. Set aside.
In a large bowl, mix eggs, oil, vanilla, and sugar.
Add dry ingredients to the wet mixture, and beat well.
Stir in zucchini and nuts (optional) until combined.
Pour batter into prepared pans and bake for 40 to 60 minutes, or until toothpick inserted in the center comes out clean.
Remove from the oven, but allow bread to cool in pan on a cooling rack for 20 minutes.
Remove bread from pan, and completely cool.