Preheat the oven to 350° F and line or grease 12 muffin tins. Set aside.
Place the shredded zucchini in a paper towel and squeeze out all excess water.
In a mixing bowl, combine the dry ingredients (brown rice flour, almond flour, baking powder, baking soda, salt, cinnamon, flaxseed).
In a second bowl, combine the wet ingredients (mashed banana, zucchini, egg, milk, maple syrup, vanilla extract).
Combine the dry ingredients to the bowl with the wet. Once fully combined, fold in the chocolate chips.
Use an ice cream scoop to scoop the batter into the prepared muffin tin, filling ⅔ – ¾ of the way full.
Bake for 18-22 minutes until the center comes out clean with a toothpick.
Once the muffins have cooled in the pan for about 5 minutes, transfer to a wire rack to finish cooling.
Store in an airtight container in the fridge for up to 5 days or freeze for a few weeks.