Preheat your oven to 350°F degrees. Line an 8.5x4.5-inch or 9x5-inch loaf pan with parchment paper. I prefer the smaller pan size for a taller loaf.
Place melted chocolate into a large mixing bowl. Whisk in maple syrup, almond butter or peanut butter and vanilla extract until smooth and fully incorporated. Whisk in eggs one at a time. Mix in grated zucchini.
Combine all-purpose flour, almond flour, baking powder, baking soda and salt in a medium bowl and whisk to blend well without any lumps. Add it to the chocolate mixture and stir gently until no dry spots remain. Fold in chocolate chips.
Scrape batter into prepared pan and smooth out the surface. Scatter extra chocolate chips on top. Bake for 40-50 minutes until the surface feels firm and a toothpick inserted into the center comes out without any wet batter. For an 9x5 inch loaf, check after 40 minutes, and for an 8.5x4.5-inch pan it will take closer to 50 minutes. It will also take longer if you use oat flour.
Let cool completely before removing from pan. Slice and serve! Store any leftovers in an airtight container in the fridge.