Place the coconut oil in a large, microwave-safe mixing bowl. Microwave for about 30 seconds, just until melted. Set aside to cool to room temperature (alternatively, you can melt the coconut oil in a small saucepan over medium heat, then transfer it to a large mixing bowl).
Preheat the oven to 350°F and line an 8 ½ x 4 ½-inch loaf pan with parchment paper so that the paper overhangs the sides like handles. Lightly coat with nonstick spray.
Press the shredded zucchini between several layers of paper towel or clean kitchen towels to remove as much excess water as possible. Set aside.
In a medium mixing bowl, whisk together the 1:1 flour, xanthan gum (if using), almond flour, cinnamon, allspice, baking powder, baking soda, and salt.
To the mixing bowl with the coconut oil, add the eggs, honey, almond milk, and vanilla extract. Whisk until smoothly combined. If the coconut oil resolidifies, heat the bowl the microwave in very short bursts (or put the bowl on top of a saucepan of simmering water if the bowl is not microwave safe), just until it liquifies again. With a rubber spatula, stir in the zucchini.
Add the dry ingredients to the bowl with the zucchini mixture. With a rubber spatula, gently stir and fold until just combined and the dry ingredients completely disappear. Do not over-mix.
Carefully fold in the chocolate chips, reserving some to sprinkle on top if desired.
Pour the batter into the prepared loaf pan and smooth the top. Sprinkle with reserved chocolate chips. Bake for 40 to 45 minutes or until a toothpick inserted in the center comes out clean—check the loaf at the 30-minute mark. If it is browning more quickly than you would like (this is the honey caramelizing) loosely tent the pan with foil to shield it, then continue baking as directed.
Place the pan on a wire rack. Let the bread cool in the pan for 20 minutes, then gently unmold it. Slice and serve warm or cooled to room temperature! (If your loaf is still warm, be sure to use a large, sharp knife to cut it. For neat slices, wipe the blade clean between each.
TO STORE: Let the bread cool completely, then store it in a paper towel-lined airtight storage container. Keep at room temperature for up to 1 week.
TO FREEZE: You can freeze this bread as slices (perfect for easy snacks) or as a loaf. Wrap zucchini bread in plastic wrap, and freeze it in an airtight freezer-safe storage container for up to 3 months. Let thaw overnight in the refrigerator.