1) Preheat the oven to 375°F. Line a 12-cup muffin pan with papers, and grease the papers; or grease each cup.
2) Beat the sugar, oil, eggs, and vanilla till smooth and somewhat lightened in color, about 1 minute at high speed.
3) Add the flour, beating just until smooth. Stir in the shredded or grated zucchini, and the orange rind.
4) Divide the batter evenly among the prepared muffin cups, filling them about 3/4 full.
5) Bake the muffins for 25 to 27 minutes, or until a cake tester inserted into a muffin comes out clean. Remove them from the oven, and after a minute or so gently tilt them in the pans, so their bottoms don't become soggy. As soon as you can handle the muffins, transfer them to a rack to cool.
6) Store leftover muffins at room temperature, tightly wrapped, for several days. Freeze for longer storage.
Yield: 12 muffins.