Pre-heat oven to 350 F.Prepare a 9-inch loaf pan.
Put shredded zucchini in a cheesecloth or with hands squeeze as much liquid as possible.
In a bowl mix flour, baking powder, baking soda, salt, and cinnamon. Whisk it well.
In another bowl add ripe banana and sugar. With the help of a fork or potato masher mash bananas until it is almost smooth.
Add eggs, oil, vanilla to the banana sugar mixture. Whisk well.
Stir in the shredded zucchini.
Add the dry ingredients in 2-3 parts to the wet mixture. First, incorporate the dry ingredients well before adding the next part.
Pour the batter into the prepared pan and bake 50 to 60 minutes until a toothpick inserted comes out clean.
Gently release the edges of the bread from the pan using a knife. Transfer the loaf to a wired rack.
Let the bread cool completely before cutting.