Preheat oven to 350 degrees. Butter then dust your loaf pan with cocoa powder.

In a large bowl, whisk together flour, cocoa powder, baking soda, cinnamon and salt.

In another large bowl, whisk together sugar and whole egg+egg yolk until smooth, about 1 minute.

Add melted butter and vanilla extract and mix until smooth.

Add zucchini, then add flour mixture in 3 additions. (I used a hand mixer for this part.)

Fold in chocolate chips.

Transfer batter (it will be REALLY thick) to your prepared pan, sprinkle the top with coarse sea salt and bake for about 50 minutes. (Test with toothpick until it comes out clean for doneness.)

Let cool slightly in pan, then transfer to a cooling rack. Best if refrigerated before you make your first cut, as it tends to crumble a bit.