Prep: Preheat the oven to 350°F. Spray a 9x13 pan with nonstick spray and set it aside.
Prepare the zucchini by grating 2 cups for this recipe. Use a paper towel to squeeze some of the extra liquid from it.*
Prep the lemons to obtain the juice and zest needed for future steps. Zest the lemon first, one large lemon should give you the 2 tsp needed for the batter. Juice the same lemon and set aside the 2 TBSPs needed for the batter and glaze.
Batter: In a medium size mixing bowl, combine the dry ingredients, the flour, salt, baking soda, baking powder, and cinnamon. Whisk to combine well.
Add in the grated zucchini, sugar, oil, eggs, vanilla extract, lemon juice, and the lemon zest. Whisk well, making sure everything is well incorporated. The batter will be thick initially, but let it sit for 5 minutes, then stir again and it should be less thick as the zucchini gives off some water.
Bake: Transfer the cake batter to the prepared pan, place it in the preheated oven and bake for 30-35 minutes. Let the cake cool in the pan before adding the topping.
Lemon icing: In a small bowl, whisk the powder sugar and lemon juice together until smooth. If icing is too thick to drizzle, add 2 tsp of hot water and whisk again. Then drizzle it over the top of the cake. Slice, serve, and enjoy!