Preheat oven to 350 degrees.
Grate 1 1/2 cups unpeeled zucchini. Do not drain or blot moisture from the zucchini.
Beat two large eggs in a large mixing bowl with a wire whisk.
Add oil, brown and granulated sugars, drained pineapple and vanilla and mix well.
Add the zucchini and stir into the wet mixture. Don't use a mixer - stir zucchini in with a wooden spoon so the zucchini remains intact.
Mix dry ingredients together in a medium size bowl. Add dry ingredients to the zucchini and pineapple mixture and mix in until combined with wooden spoon.
Add chopped nuts and stir into the batter (optional).
Put batter in a 9x5 loaf pan that has been sprayed well with non-stick spray. You may line the pan with parchment paper if you desire.
Bake in a pre-heated 350 degree oven for 45-50 minutes or until a toothpick inserted in center of loaf comes out clean.
Let the bread cool in the pan for about 5 minutes and then invert onto a cooling rack. Let the bread cool before slicing it.
Yield is one loaf of bread and 12 servings.