Preheat your oven to 350 degrees.
Grease a 9 x 5 loaf pan and set aside.
In a large bowl, mix together the applesauce and sugar.
Add in the eggs and mix.
Add in the shredded zucchini, water, and vanilla. Stir together.
Add in the flour, baking powder and soda, salt, cinnamon, and nutmeg. Blend together.
Pour half of the batter into your prepared loaf pan.
To the remaining batter, add in the cocoa powder and chocolate chips and stir to fully incorporate.
Pour the chocolate batter on top of the plain batter.
Insert a butter knife and gently swirl to make a marbled pattern. Don't overmix or you'll end up with all chocolate bread.
Bake for approximately 1 hour or until a toothpick inserted in the center comes out clean.