Wash and shred the zucchini. Line the bottom of an 8 1/2 x 4 1/2" bread pan with parchment paper. Spray with cooking spray. Preheat oven to 325°.
Whisk together the sugar, oil, eggs, vanilla, zucchini, and pineapple in a large bowl.
In a small bowl, whisk together the flour, baking powder, soda, and salt. Add to the zucchini mixture and gently stir the mixture together.
Pour batter into the prepared loaf pan. Bake in a preheated oven at 325° for 50-55 minutes, or until a toothpick inserted in the middle comes out clean (moist crumbs are fine).
Let cool in the pan for about 10 minutes, then invert onto a wire rack to cool completely.
For icing, whisk together the powdered sugar, pineapple juice, and salt in a small bowl. Drizzle over the cooled bread.
Notes
Serving is based on each loaf being cut into 12 slices and includes icing.