Make the flax eggs by stirring together the ground flax and water. Let sit for about 5 minutes to thicken. Preheat oven to 375°F and grease a mini muffin tin.
In a large bowl, whisk together the dry ingredients: both flours, cinnamon, pumpkin pie spice, baking powder, baking soda, and salt.
In a separate bowl, combine the wet ingredients: flax eggs, pumpkin puree, maple syrup, avocado oil, and vanilla.
Add the wet ingredients to the dry and mix until just combined. Fold in the shredded zucchini and chocolate chips.
Divide the batter evenly among the muffin cups and sprinkle with oats, if desired.
Bake for 13 minutes, or until a toothpick inserted in the center comes out clean.
Cool for 5 minutes, then remove to a cooling rack.