Grate zucchini, mash banana, and chop/crush walnuts, then set aside.
In a large mixing bowl, stir together dry ingredients: ground flaxseed, flour, brown sugar, baking soda, baking powder, cinnamon and salt.
Next add the zucchini, banana, and walnuts and stir to combine. In a separate bowl, whisk together your egg, milk, applesauce and vanilla.
Add the wet mixture to the dry mixture and stir until just combined [try not to over-mix if possible].
Spritz three mini loaf pans [or muffin tin!] with olive/coconuut oil or grease with coconut oil to prevent sticking and add the batter, filling each about halfway.
Bake for 20-25 minutes for a tray of muffins, 25-35 for mini loaves [my favorite!], and about 45-55 minutes for a large loaf.
Test the center with a toothpick and, once it comes out squeaky clean, pull em out! I'm a neurotic baker and check mine about 2-3x before yanking them from the oven. It pays off =)
Remove and place on a wire cooling rack, resisting the urge to run off with a face full of bread.
To make a flax egg: scoop 1 tablespoon of ground flax into a small bowl and slowly add 3 tablespoons of water, whisking as you combine the two. Place in the fridge for a minimum of 15-20 minutes or even an hour if you plan ahead (not my forte). Once it reaches an eggy consistency you're ready to go!