Preheat oven to 400 degrees. Grease 18 muffin cups and set aside.
In a large mixing bowl, beat eggs. Whisk in oil, vanilla and sugar. Stir in zucchini. Measure flour, baking soda, baking powder, salt and cinnamon into a sifter and sift the dry ingredients into the zucchini mixture in bowl. Stir just until combined.
Fill prepared muffin tins 3/4 to the top. Bake 15 to 20 minutes until tops of muffins spring back when pressed lightly with your finger. Top of muffins should not look moist. Remove from oven. Run a table knife around each muffin. Allow to cool 5 to 10 minutes in the pan before removing and transferring to a wire rack to cool completely. Makes about 1 1/2 dozen muffins.