1. Preheat oven to 350 degrees Fahrenheit. Prepare two mini loaf pans with a light coating of nonstick spray.
2. In a food processor, blend flour, sugars, baking soda, baking powder, salt and cinnamon for 10 seconds. Empty into a large mixing bowl. Process walnuts (if using) until chopped, about five seconds. Empty into a small bowl.
3. Grate zucchini and measure two cups, loosely packed.
4. Using the food processor, blend eggs, then add oil, vanilla and zucchini and process until blended. Add dry ingredients and pulse quickly, five to six times.
5. Fill mini loaf pans until just under half full. Bake for 20-30 minutes, or until a toothpick inserted into the middle of a loaf comes out clean. Cool on a wire rack.
6. Serve warm or at room temperature.