Preheat oven to 350° F. Spray a 9"x5" loaf pan with baking spray.
In a small mixing bowl, add the flour, cocoa, baking soda, baking powder, salt, espresso powder. Mix together.
In a Medium mixing bowl, add the room temperature eggs, oil, brown sugar, vanilla, and the cooled melted butter (by cooled I mean that it is still pourable, but not warm enough to affect the eggs). Whisk together well.
Add the dry ingredients to the wet and fold together with a spatula. It's okay if not thoroughly mixed. You don't want to over mix this batter.
Add the zucchini and gently fold into the batter.
Add 1 cup of the chocolate chips and gently fold in. Save the remaining ¼ cup.
Pour the batter into the prepared loaf pan and use a spatula to spread evenly in the pan.
Sprinkle the remaining chocolate chips on top. Bake for 50-60 minutes, or until a toothpick inserted into the center comes out clean of batter (may have some melted chocolate on it).
Allow to cool in the pan for about 15 minutes, then use a butter knife to loosen the edges and carefully remove to finish cooling on a wire rack.
Serve warm or room temperature.