Preheat the over to 350° Spray two 9"x5" loaf pans with oil
In a large bowl, whisk together the flour, cocoa powder, baking soda, baking powder, and salt.
In another bowl, combine the sugar, eggs, applesauce, oil, and vanilla.
Stir the grated zucchini into the sugar / egg mixture
Add the zucchini mixture to the dry ingredients and stir until just combined.
Fold in the chocolate chips
Spread the batter, in the prepared pans, divided evenly.
Bake 50 minutes or until a toothpick inserted in the centre comes out clean.
Cool in the pans 10 minutes before transferring the loaves to a wire rack to cool completely before slicing.
Notes
I use a food processor with the grating attachment to grate the zucchini, but you can also do it manually using a box grater.
Be careful not to overmix the batter. The key to a tender, moist zucchini bread is to heed the direction "stir until just combined". This usually takes about 10 seconds. Overmixing will result in a rubbery, dense loaf.
This gluten-free zucchini bread recipe uses a 1:1 ratio gluten-free flour blend. Because of that, you can easily use regular wheat flour if gluten isn't a problem for you.
The flour blend that I use contains xanthan gum. Check the label of the gluten-free flour blend you are using. If it doesn't contain xanthan gum you will need to add it to the dry ingredients. Use 1 teaspoon per cup of flour.
This is a dairy-free recipe. However, if dairy is a problem for you, check the label of your gluten-free flour blend. Some of them contain milk powder.
To freeze, cool the loaves completely, then wrap them in foil and then plastic. Or, you can slice the cooled loaves and wrap individual slices in plastic wrap before freezing. Freeze for up to three months.
Store the zucchini bread on the counter for a day or two, and up to a week in the fridge. Store in an airtight container.