Preheat the oven to 350 degrees F. Lightly grease a 9-inch square baking pan with cooking spray. Set aside.
In a large bowl, stir together the cornmeal, flour, sugar, baking powder, baking soda, and salt.
Make a well in the dry ingredients and add the buttermilk (or milk), eggs, and melted butter (or coconut oil) and zucchini. Stir just until combined.
Spread the batter in the prepared pan and bake for 30-32 minutes until the top springs back lightly to the touch and/or a toothpick inserted in the center comes out clean.
Notes
Flour: this bread is equally delicious, albeit slightly heartier, with white whole wheat flour in place of the all-purpose flour (or 50% of each works great, too). Zucchini Tutorial: here's a quick video tutorial on wringing out zucchini. For this recipe, you want the zucchini fairly dry. It's ok if there's still a little moistness to it but you definitely don't want it dripping wet.