To begin, preheat your oven to 350 and spray a muffin pan with non-stick spray. Alternatively, you can use cupcake liners.
In a small mixing bowl, add your dry ingredients and stir them together (oat flour, baking powder, baking soda, salt).
In a large mixing bowl, add your sugar, applesauce, coconut oil, lemon juice and lemon zest and whisk them together till well combined. Add your vanilla and eggs and whisk again.
Pour your dry ingredients into your wet ingredients and stir together till you have one consistent muffin batter.
Add your shredded zucchini (and walnuts, if using) to the batter and gently fold them in.
Scoop the batter into your muffin tin, filling each cavity about 3/4 way full. Bake in the oven for 15-17 minutes, or till the tops of the muffins are springy to touch and a toothpick inserted comes out clean.
Let cool, then carefully remove from the muffin tray.
Devour!
These muffins can last in an airtight container stored on the counter for about 2-3 days, or up to a week if stored in the fridge. You can also freeze these muffins.