Wash and cut the ends off of the zucchini. Shred the zucchini with a cheese grater or a food processor using the grating attachment. Once the zucchini is shredded, transfer to a bowl and set aside for later.
2 (260g) cups finely shredded zucchini
Please note if you're fermenting this batter overnight you can shred the zucchini the next day as you will add it then.
Whisk together the oil, sour cream, sourdough discard, brown sugar, eggs, and vanilla until smooth in a mixing bowl.
½ (120g) cup avocado oil , ⅓ (80g) cup full-fat sour cream, ½ (120g) cup sourdough discard, 1 (200g) cup brown sugar, ⅓ (65g) cup granulated white sugar, 3 large eggs, 2 tsp vanilla extract
In a separate bowl, whisk together the flour, cocoa powder, baking soda, baking powder, salt, cinnamon, and espresso powder until all of the ingredients are combined.
2 (275g) cups all-purpose flour, ½ (50g) cup cocoa powder, 1½ tsp baking powder, ½ tsp baking soda, 1 tsp fine sea salt, 1 tsp ground cinnamon, ½ tsp espresso powder
Add the dry ingredients to the wet ingredients, and gently whisk the batter until no streaks of flour remain. Be careful not to overmix the batter at this stage or the crumb will be tough.
Add the shredded zucchini and chocolate chips to the batter and fold into the batter until just incorporated. Avoid overmixing.
1 (170g) cup semisweet chocolate chips
Overnight ferment option: To ferment this batter, don't add the shredded zucchini or chocolate chips to the bread yet or the bread will be gummy. Cover the batter after adding the dry ingredients and transfer to the refrigerator overnight for optional fermentation.