Preheat oven to 350 and prepare a muffin pan. I use a silicone muffin pan so there is no need to grease it.
Mash the bananas in a large bowl. Add the remaining wet ingredients. There is no need to squeeze the water out of the zucchini. Add maple syrup to taste. You'll need less if you're using very ripe bananas and chocolate chips, but may want more if you're used to sweeter muffins. Up to you! I wouldn't use less than 1/3 cup unless you need to for dietary reasons.
In another bowl, mix the dry ingredients.
Stir all together. Do not overmix.
Spoon the batter into the muffin cups until all 12 are evenly filled. Bake for 25 minutes. Let cool at least 20 minutes before removing from the pan to enjoy.
These keep well on the counter or the fridge for 2 days, or in the freezer for several months.
Notes
You can make this into one large loaf or three mini loaves, as well. Bake a large loaf for about 55 minutes, and small loaves for 30-35 minutes. For gluten-free: use 1.25 cups oat flour, 1/2 cup all-purpose gluten-free flour, and 1/4 cup almond flour. SO GOOD.