Preheat the oven to 350 degrees F. Lightly grease a 12-cup muffin tin with non-stick cooking spray, or line it with paper liners.

Dry ingredients: In a large bowl, whisk together the flour, sugar, soda, cinnamon and salt. (Fluff the flour a little before spooning it into the measuring cup to make sure it's not packed too tightly).

Wet ingredients: In a separate bowl whisk together the oil, mashed banana, buttermilk, egg and vanilla.

Grate and measure out the zucchini, then gather the grated zucchini in your hands and squeeze it over the sink to get rid of excess moisture. Stir into wet ingredients.

Combine: Stir in dry ingredients and chocolate chips, just until combined (don't over-mix the batter).

Bake: Divide the batter evenly among the muffin cups, filling them about 2/3 full. This recipe will make 12 smaller muffins, or 10 medium size muffins. Bake for 17-18 minutes until the tops of the muffins spring back lightly to the touch.

Remove the muffins to a cooling rack to cool completely.