1 1/2 cups all-purpose gluten-free flour
1/2 teaspoon xanthan gum (omit if your blend already contains it)
1/2 teaspoon kosher salt
1/2 teaspoon baking soda
1/2 teaspoon baking powder
1 teaspoon ground cinnamon
2/3 cup semi-sweet chocolate chips
1/2 cup granulated sugar
1/2 cup packed light brown sugar
2 1/8 cups grated zucchini
2 eggs at room temperature
1/4 cup neutral oil (like grapeseed, canola or vegetable oil)
1 teaspoon pure vanilla extract
Preheat your oven to 325°F. Grease a standard 9-inch x 5-inch loaf pan and set it aside.
In a large bowl, place flour, xanthan gum, salt, baking soda, baking powder and cinnamon, and whisk to combine well. Place the chocolate chips in a small bowl, add about 1 teaspoon of the dry ingredients to the chips and toss to combine. Set the chips aside. To the flour mixture, add the granulated sugar and light brown sugar, and whisk to combine (working out any lumps in the brown sugar). Add 1 1/4 cups (125 g) of the grated zucchini to the dry ingredients, and mix gently to combine. Set aside the dry ingredients.
Place the remaining 7/8 cup (88 g) of grated zucchini, the eggs, oil and vanilla in a blender, and pulse until well-blended and beginning to emulsify. Create a well in the center of the bowl of dry ingredients, and add the wet ingredient mixture. The batter will be very wet. Add about 1/2 cup of the chocolate chips and reserved dry ingredients to the batter and mix until the chips are evenly distributed throughout the batter. Scrape the batter into the prepared loaf pan, and smooth the top with a wet spatula. Scatter the remaining chocolate chips on top and press down lightly to adhere.
Place the loaf pan in the center of the preheated oven. Bake, rotating once, until the top is golden brown and a toothpick inserted in the center of each loaf comes out with a few moist crumbs attached (about 50 minutes). Remove from the oven and allow to cool for at least 30 minutes in the loaf pan before transferring to a wire rack to cool completely before slicing and serving.