In a medium mixing bowl, combine all the dry ingredients—gluten-free flour, almond flour, baking powder, baking soda, salt, cinnamon, and nutmeg—whisking until evenly mixed.
To the dry mixture, add brown sugar, white sugar, eggs, vegetable oil, almond milk, lemon juice, and vanilla extract. Blend with a hand mixer on low speed until a smooth batter forms.
Gently fold the grated zucchini into the batter, mixing on low speed for about 30 seconds. Then, incorporate your choice of chopped walnuts or chocolate chips.
Distribute the batter evenly into the prepared pans. Bake for 30 to 35 minutes, or until a toothpick inserted into the center comes out clean and the bread feels firm.
Allow the bread to cool in the pans for 10 minutes. Carefully remove the loaves and transfer them to a wire rack to cool completely. Wrap any leftovers in plastic wrap and store at room temperature. Enjoy your moist zucchini bread!