Preheat oven to 325 degrees F (165 degrees C). Grease and flour two 8x4 inch loaf pans.
In a large bowl, combine flour, baking soda, baking powder, salt and cinnamon. In another bowl, beat together eggs, oil, sugar and vanilla. Stir in zucchini. Gradually add dry ingredients to wet ingredients; mix just until blended.
Divide batter between prepared pans.
Bake for 40 to 60 minutes or until a toothpick inserted into the center of the loaf comes out clean. Cool in pan on rack for 20 minutes. Remove bread from pan, and completely cool.