Preheat oven to 325°F. Grease a 8 ½-inch x 4 ½-inch loaf pan with nonstick spray.
In a large bowl, mix together zucchini, oil, eggs, and vanilla extract.
Whisk sugar into the zucchini mixture until the sugar completely dissolves and the mixture is creamed together.
In a separate bowl, sift together flour, salt, cinnamon, baking soda, and baking powder. Add the sifted dry ingredients to the wet ingredients. Stir just until combined. The batter should be smooth, with the exception of the shredded zucchini.
Transfer batter to prepared pan.
Bake for approximately 55 minutes, or until bread springs back when gently pressed in middle and a toothpick inserted in the center comes out clean.