Preheat the oven to 350. Shred zucchini in a food processor or with a box grater. Transfer zucchini to a bowl lined with cheesecloth or a towel. Gather fabric around zucchini and squeeze out excess water. Return to bowl and allow to dry further.

In a large bowl, mix together flour, salt, baking soda and powder, and spices. Set aside. 

In a small bowl combine egg, vanilla extract, sugars, oil and applesauce. If using the dried lemon zest, add to wet ingredients and allow to rehydrate for 10-15 minutes. 

Next, coat blueberries in one tablespoon of cornstarch to prevent them from sinking as they bake. The cornstarch also acts as a drying and binding agent to counteract some of the moisture released by the blueberries as it bakes. 

Gently fold zucchini and blueberries into the flour mixture. I used my hands to lightly toss the zucchini in the flour first, to make sure the zucchini shreds are fully coated in flour. Finally, gently toss the blueberries into the flour mixture. 

Add the wet ingredients to the dry ingredients and fruit, and gently stir to combine. 

Transfer batter to greased and parchment lined 8.5 x 4.5 (medium) loaf pan. You can use a 9x5 pan, however the loaf won't bake up quite as tall. 

Bake at 350 for 50-60 minutes. Remove from the oven to cool, in pan, for 15 minutes, on its side. Then, remove loaf from pan to cool completely