Shred the zucchini and gently squeeze out most of the moisture, leaving a little for softness.
Whisk together the flour, baking soda, baking powder, salt, cinnamon, and nutmeg.
In a separate bowl, mix mashed bananas, eggs, melted oil, sweetener, and vanilla.
Stir the shredded zucchini into the wet mixture.
Add the dry mixture to the wet mixture and stir just until the flour disappears.
Fold in nuts, chocolate chips, or any other add-ins.
Preheat oven to 350°F (175°C).
Grease a loaf pan or line it with parchment paper.
Pour the batter into the pan and smooth the top.
Bake for 50–60 minutes, or until a toothpick inserted in the center comes out clean.
Let the bread cool completely before slicing.