Preheat your oven to 350°F (175°C). This ensures the muffins bake evenly and rise beautifully.
Grate the zucchini using a box grater or food processor. Measure out about 2 cups of grated zucchini. Place the zucchini in a clean kitchen towel or cheesecloth, and squeeze out as much moisture as possible. Set aside.
In a large mixing bowl, combine the mashed bananas, melted coconut oil, honey, eggs, and vanilla extract. Whisk until the mixture is smooth and well combined.
In a separate bowl, whisk together the whole wheat pastry flour, baking soda, ground cinnamon, and kosher salt.
Gradually add the dry ingredients to the wet mixture, stirring gently with a spatula until just combined. Be careful not to overmix; a few lumps are okay.
Gently fold in the grated zucchini and chocolate chips, ensuring they are evenly distributed throughout the batter.
Line a muffin tin with paper liners or grease it lightly with cooking spray. This will prevent the muffins from sticking.
Scoop the batter into each muffin cup, filling them about 2/3 full to allow for rising.
Place the muffin tin in the preheated oven and bake for 18-22 minutes, or until a toothpick inserted into the center comes out clean.
Once baked, remove the muffins from the oven and allow them to cool in the tin for about 5 minutes. Then transfer them to a wire rack to cool completely.
In a small bowl, mix together the softened salted butter, honey, and ground cinnamon until creamy and well combined. Set aside until ready to serve.
