Preheat your oven to 325 degrees F (165 degrees C). Grease and flour two 8×4 inch loaf pans to ensure the bread doesn’t stick after baking.
In a large bowl, whisk together the flour, salt, baking powder, baking soda, and ground cinnamon. Sifting helps remove lumps and ensures the spices are evenly distributed.
In a separate medium bowl, beat the eggs until light and fluffy. Add the vegetable oil, sugar, and vanilla extract. Whisk together until the mixture is smooth and well combined.
Add the egg mixture to the dry ingredients and stir until just blended. Fold in the grated zucchini and chopped walnuts. Be careful not to overmix, as this can make the bread tough.
Pour the batter evenly into the prepared loaf pans. Bake for 40 to 60 minutes, or until a toothpick inserted into the center comes out clean. Let the pans cool on a wire rack for 20 minutes before removing the bread.