*I've said it many times but different cocoas will produce different flavors. One of my favorite cocoas to use is Double Dutch Dark Cocoa For this recipe, I used Bensdorp Cocoa. Love 'em both. You can use regular unsweetened cocoa, but I love the flavor that Dutch process cocoa provides.
*You can use zucchini or yellow squash in this recipe.
*I tried both semi-sweet and bitter sweet chips and preferred the semi sweet. You could also use milk chocolate chips, if you're looking for more sweetness.
*Processing the mixture does create air bubbles in the batter. You'll see little holes on the surface of my baked brownies from the bubbles that popped in the oven. (A couple are just from my testing toothpick.) I should have dropped the pan on the counter a few times to release them. I've added that step to the instructions. If you decide to frost the brownies, you won't see them anyway.
*If you don't have a food processor, you can puree the zucchini and wet ingredients in a blender, pour it into a bowl, then stir in your dry ingredients.
*You don't have to store these in the refrigerator, but I really like them cold. For the best cuts, cut cold brownies with a hot knife. I just let my knife sit in a tall mug of hot water for a minute or two, then wipe it dry and cut. I reheat it in the water every couple of cuts wiping the blade with a paper towel after each dip in the water.
Recipe from King Arthur Flour