Preheat your oven to 350ºF and grease a 4x8 loaf pan. Set the pan aside.
Add the flour, baking powder, baking soda, cinnamon, salt, and nutmeg to a mixing bowl. Whisk together and set aside.
1½ cups flour, 1½ teaspoons baking powder, 1 teaspoon baking soda, 2 teaspoons cinnamon, ¼ teaspoon ground nutmeg, ½ teaspoon salt
Add the grated zucchini to a medium-sized bowl. Use your hands to squeeze the zucchini, discarding any water that comes out of the veggie. You want the grated zucchini to be as dry as possible.
1½ cups zucchini
Add the banana and eggs to the bowl with the zucchini and mix together well.
2 bananas, 2 eggs
Add the brown sugar, vanilla, and oil to the zucchini bowl and mix until evenly combined.
½ cups brown sugar, 2 teaspoons vanilla, ½ cup vegetable oil
Add the flour mix into the bowl with the zucchini mix and blend everything together. The batter should be nice and thick.
Pour the batter into the prepared pan and bake for 45 minutes. The top should be browned, and a toothpick inserted into the center of the bread will come out cleanly.
Let the loaf pan cool in the pan for about 15 minutes then flip the bread out of the pan and let it continue to cool on a cooling rack. Slice and serve!