Preheat the oven to 375 degrees F. Lightly grease a standard 12-cup muffin tin or line with paper liners.
Grate the zucchini, then throughly squeeze it with a paper towel to remove as much excess water as possible. Repeat as needed. If you have not already, melt the coconut oil and let come to room temperature
In the bowl of a standing mixer or a large mixing bowl, beat together the banana, honey, brown sugar, coconut oil, and vanilla extract until smooth. Add the eggs (make sure they are room temperature or the coconut oil may resolidify), then beat again until combined.
Sprinkle the cinnamon, baking soda, baking powder, and salt over the top of the batter, then mix to combine. Sprinkle in the flour, then mix on low speed, just until the flour disappears. By hand, fold in the zucchini and chocolate chips.
Scoop the batter into the prepared muffin cups, filling them 3/4 of the way. Bake for 20-25 minutes, until a toothpick inserted in the center comes out clean. Remove the muffins from the oven and place the pan on a wire rack. Let cool for 5 minutes in the pan, then carefully lift the muffins out of the pan and place them on a wire rack to cool completely (this will keep the muffins from becoming soggy).
Store muffins at room temperature according to my guide to store muffins, or individually wrap and freeze for up to 3 months. Let thaw overnight in the refrigerator (or if you are in a hurry, unwrap and microwave gently on reduced heat until warm).
For tips to make the muffins vegan or gluten free, see blog post above.
For even more suggestions for how to vary up the recipe (adding oatmeal, using flaxeggs, etc.) skim the comments. There are many helpful suggestions from those who have reported making (and loving!) these muffins.