Preheat oven to 375 degrees F and spray non-stick 12 muffin tin with cooking spray. Set aside.
In a large mixing bowl add eggs, applesauce, maple syrup, oil, vanilla extract, cinnamon, baking powder, baking soda and salt; whisk well to combine.
Add flour and gently mix with spatula just until combined. Add zucchini and nuts (if using). Stir and do not over mix.
Distribute batter evenly between 12 openings of a tin (I used trigger cookie dough scoop) and bake for 20 minutes or until a toothpick inserted in the center comes out clean.
Let muffins cool for a few minutes and transfer to a cooling rack to cool off for another 30 minutes.
Video
Notes
Store: Store muffins on a counter covered with linen towel or in a ventilated container for 1-2 days. After I recommend to freeze them.
Freeze: Bake and cool muffins completely. Place in resealable plastic bag, let the air out as you are sealing, and freeze for up to 3 months. Thaw on a counter for a few hours.