For light-colored aluminum pans, heat the oven to 350°F (175°C). For oven-safe glass pans, use 325°F (165°C) and allow extra baking time as needed. For cast iron, follow the pan manufacturer’s guidance and the pan-material notes below. Grease two 9-by-5-inch loaf pans and line them with parchment paper, leaving overhang for lifting.
Shred enough zucchini to measure 2 1/2 cups loosely packed. If it has released a puddle of liquid, drain that free liquid; do not wring the shreds dry.
2½ C Shredded Zucchini
In a large bowl, mix 2 1/2 cups shredded zucchini, 1 cup unsweetened applesauce, 1 cup granulated sugar, 1 cup brown sugar, 3/4 cup oil, and 2 teaspoons vanilla extract.
1 C Unsweetened Applesauce, 1 C Sugar, 1 C Brown Sugar, ¾ C Olive oil, 2 tsp Vanilla Extract
In a second bowl, whisk 3 cups all-purpose flour, 1 teaspoon salt, 1 teaspoon baking soda, and 2 teaspoons cinnamon.
3 C All-Purpose Flour, 1 tsp Salt, 1 tsp Baking Soda, 2 tsp Cinnamon
Add the dry mixture to the wet mixture and stir just until no dry flour remains.
Let the batter rest for 15 minutes.
Divide the batter evenly between both pans and smooth the tops. Do not put the whole batch into one loaf pan. Bake on the center rack with space between the pans. For aluminum pans, allow approximately 50 to 65 minutes. Glass pans at 325°F may need longer; continue until the centers are done.
Begin checking both loaves at 45 minutes. Continue baking until a skewer inserted in the center has no wet batter and the center is set. An instant-read thermometer should register about 200 to 205°F in the center. If the tops brown before the centers are done, tent loosely with foil and continue baking.
Cool in the pans for 15 minutes, then lift onto a wire rack and cool completely before slicing. Cut each loaf into 8 slices, for 16 slices total.