Preheat the oven to 350 degrees. Butter two 5x9-inch loaf pans. Place the grated zucchini in a sieve or colander over a bowl to drain any excess moisture. In a large bowl, whisk together the flour, baking soda, cinnamon, ginger and ground nutmeg. In another large bowl, whisk together the sugar, eggs, vanilla extract, and salt (omit salt if using salted butter). Stir in the drained grated zucchini and then the melted butter. Add the flour mixture, a third at a time, to the sugar/egg/zucchini mixture, stirring after each incorporation. Fold in the nuts and dried cranberries or raisins if using. Divide the batter equally between the loaf pans. Bake for 50 minutes at 350 degrees or until a tester inserted into the center comes out clean. Cool in pans for 10 minutes. Turn out onto wire racks to cool thoroughly.