Preheat the oven to 350°F. Place muffin liners into a standard, 12-muffin pan. Set aside.
Prepare the flax egg: Combine 1 tbsp ground flax with 2 tbsp purified water, mix well, and let sit for 10-15 minutes.
Using a grater, shred 2-3 zucchini until you have 2 cups of shredded zucchini. Using a paper towel or clean cloth, gently squeeze the liquid from the zucchini. (You should have about 1/4 cup liquid drained).
Combine all the dry ingredients (except the almond meal) into a large mixing bowl.
In a separate large mixing bowl, combine the wet ingredients and zucchini. Mix well.
Slowly add the dry mix to the zucchini mixture. After the ingredients are fully combined, add 1-3 tablespoons of almond meal as needed to absorb any excess moisture.
Fold in the blueberries and your choice of mix-ins. Then evenly distribute batter among muffin tins, filling each about 3/4 of the way full.
Bake for 25-30 minutes or until toothpick inserted into the middle of the muffin comes out clean.
Remove from the oven and allow the muffins to cool inside the muffin tin for 10 minutes then remove muffins and transfer to a wire rack to finish cooling for 5 minutes.