Wash your zucchini, keep the peel on and grate it on the fine side of a box grater into a bowl.
In a large bowl, whisk together the oil, eggs, sugar, yogurt, sour cream, and vanilla extract until everything is combined.
Sieve the flour, cocoa powder, baking soda, baking powder, and salt into the same bowl.
Fold everything together with a spatula or wooden spoon until just combined.
Add most of your chocolate chips and gently fold them into the batter. Don’t overmix;
Line a 12-cup muffin tin with paper liners or grease it well
Using an ice cream scoop fill the muffin tins.
Sprinkle the reserved chocolate chips on top of each muffin.
Bake in a preheated oven at 375°F (190°C) for 18 to 22 minutes. Start checking at 18 minutes
Insert a toothpick into the center of a muffin; it should come out with a few moist crumbs, not wet batter. If it comes out completely clean, they might be slightly overbaked. You’re aiming for moist crumbs.
Remove from oven and let the muffins cool in the tin for 5 minutes before transferring them to a wire rack.
After that, cool them on the rack for another 10 minutes before eating if you can wait that long.
