Preheat your oven to 350 degrees F. Lightly butter a 9 x 5 loaf pan and set aside.
Whisk together flour, granulated sugar, baking powder, cinnamon, salt and lemon zest in a large bowl.
In a separate medium bowl, whisk together oil, eggs and lemon juice until well combined. Stir in the shredded zucchini.
Add the wet zucchini mixture to the dry flour mixture and stir to combine (do not over-mix).
Transfer the batter to prepared loaf pan and spread evenly. Bake for 45 to 50 minutes, or until a toothpick inserted in the center is removed clean.
Cool on a wire rack for 15 minutes, then carefully remove the bread from pan, place on the rack and allow to cool completely.
While the bread is cooling, prepare the glaze by whisking or stirring together powdered sugar, lemon juice and lemon zest in a small bowl until smooth.
Drizzle glaze over cooled bread.