Preheat oven to 350°F. Grease two 9x5 loaf pans.
In a medium bowl, whisk together flour, cinnamon, baking powder, baking soda, and salt.
In a large bowl, whisk together eggs, oil, sugar, and vanilla.
Fold flour mixture into egg mixture until combined. Fold in zucchini and nuts.
Divide batter between the two loaf pans and bake for about an hour, or until a skewer inserted into the center comes out clean.
Let cool in pans for 30 minutes, then run a knife around the edge to release, and cool completely.