In a mixing bowl stir together flour, salt, baking powder, baking soda, and cinnamon. Set aside.
In the bowl of a stand mixer, beat eggs, oil, vanilla, and sugar together.
Reduce speed and add dry ingredients to the creamed mixture, and blend well.
Stir in zucchini and chopped nuts.
Divide batter evenly between prepared loaf pans.
Bake for 30 minutes and remove loaves from the oven.
Evenly distributed crumb topping between the two loaves, spreading out crumb topping as evenly as possible.
Return loaves to the oven and continue baking for another 30 to 50 minutes, or until a toothpick inserted in the center of the loaf comes out clean.
Cool loaves in the pan for 20 minutes.
Remove loaves from the pans. Run a knife along outer edges of pan to loosen loaves if not popping out of the pans easily. Allow loaves to cool completely.