Preheat your oven to 350°F and line a muffin tin with paper liners. This step ensures the muffins bake evenly and come out easily.

Grate the zucchini finely and wrap it in a clean kitchen towel. Squeeze out any excess moisture to prevent soggy muffins. Set it aside for later.

Combine flour, cinnamon, baking powder, baking soda, and kosher salt in a large mixing bowl. Stir until the ingredients are distributed evenly.

Mash the ripe bananas in a separate bowl. Add sugar, eggs, oil, and vanilla extract. Whisk together until fully combined and smooth.

Gradually pour the wet mixture into the dry ingredients. Stir gently until just combined, then fold in the shredded zucchini. Avoid overmixing.

Spoon the batter into the prepared muffin tin, filling each liner about ¾ full. Bake in the preheated oven for 22-26 minutes, or until a toothpick inserted in the center comes out clean.

Once done, cool the muffins in the tin for about 10 minutes. Then transfer them to a wire rack to cool completely. Enjoy warm or at room temperature!