Grate 3 cups of zucchini or use frozen zucchini shreds.
Place freshly grated or frozen zucchini shreds in a colander in the sink, wrapped in several layers of paper towels. Press out the moisture in the zucchini and set aside.
Beat eggs in a large mixing bowl. Add oil and brown sugar; beat well. Stir in vanilla and zucchini.
Combine flour, salt, baking soda, baking powder, cinnamon, nutmeg and cloves. Add to zucchini mixture and beat well. Stir in chocolate chips.
Pour into prepared pans and bake about 1 hour or until toothpick inserted in center comes out clean.