Preheat oven to 350°F and prepare a muffin tin by spraying well with cooking spray or line the tins with paper or silicone liners. Set aside.
Measure 1 cup of grated zucchini then wrap the zucchini in paper towels (or a kitchen towel) and squeeze out as much liquid as possible. Discard liquid.
Add zucchini, almond butter, maple syrup, eggs, cinnamon, vanilla, baking powder and salt to a medium mixing bowl. Mix until well combined and then gently stir in chocolate chips.
Fill each muffin cavity about ¾ full with the muffin mixture. Top with extra chocolate chips, if desired.
Bake for 20-23 minutes, or until the tops are set and a toothpick inserted into the center comes out clean without any batter. Allow muffins to cool for 5-10 minutes or until they are firm enough and cool enough to handle. Remove from tin and let cool completely on a wire rack. If they're sticking at all, use a butter knife to go along the rim of the muffin tin to help you detach the muffin from the tin and get them out in one piece.
Muffins are always best fresh, but these will keep airtight in the fridge for about 5 days, or in the freezer for up to 4 months.