Preheat your oven to 350°F (175°C) and grease a 9x5 inch loaf pan.
In a mixing bowl, combine mashed bananas with grated zucchini.
Add both sugars, oil, eggs, and vanilla extract to the mixture.
In a separate bowl, whisk together flour, baking soda, baking powder, salt, and cinnamon.
Gradually mix the dry ingredients into the wet ingredients until just combined.
Fold in walnuts or chocolate chips if desired.
Pour the batter into the prepared loaf pan.
Bake for 50-60 minutes, or until a toothpick inserted in the center comes out clean.
Cool in the pan for 10 minutes before transferring to a wire rack.
Slice and enjoy your zucchini banana bread!