Preheat oven to 325 degrees. In a small bowl, combine 1/4 c sugar and 1 t cinnamon. Grease loaf pans and coat with cinnamon-sugar mixture. Set aside. In a large mixing bowl, combine eggs, oil, sugar, zucchini, and vanilla. Add dry ingredients. Divide batter evenly between 2 loaf pans. Sprinkle the top with remaining cinnamon-sugar mixture. Bake for 1 hour. For muffins: Line muffin tins with paper liners instead of greasing and sugaring the pan. Fill muffin tins 2/3 full. Sprinkle the top of each muffin with about 1 t cinnamon-sugar mixture. Bake for 30-45 minutes, or until a toothpick inserted in the center of a muffin comes out clean.