Preheat oven to 325 degrees F and grease a 9" x 5" loaf pan.
In a microwave-safe bowl soften the butter then stir in the sugar and combine well. Add the eggs and vanilla extract, stirring to combine well again.
In a separate bowl whisk together the flour, cocoa powder, baking powder, baking soda, and salt.
Add the dry ingredients to the wet ingredients and stir until combined.
Stir in the zucchini and chocolate chips. Pour the batter into a greased loaf pan and sprinkle with a few more chocolate chips.
Bake in a preheated oven for 60-75 minutes.
Allow the bread to set in the bread pan at least 30 minutes, so the bottom doesn’t stick when removing.
To shred zucchini; use a box grater. To purée zucchini; use a food processor and pulse until somewhat smooth, but not too fine.
You can also use frozen zucchini, just make sure it's thoroughly defrosted before adding it to the recipe.
The bread is perfectly baked when it's golden brown and the top is firm but just a bit soft in the middle. Remove from oven when a toothpick inserted comes out a little sticky, but not wet. The bread will continue to cook a little in the pan after it's removed from the oven.
This bread can be cooled for a couple of hours and it shouldn't stick to the pan. I know, because I cooled my Chocolate Chip Zucchini Bread for a couple of hours and it came out easily.