Preheat the oven to 350°F. Line a 9-inch loaf pan with parchment paper then grease the parchment paper with cooking spray.
In a medium bowl, whisk together flour, brown sugar, baking soda and salt.
In a separate medium bowl, whisk together the bananas, Greek yogurt, eggs, zucchini, olive oil and vanilla extract.
Add the wet ingredients to the dry ingredients and stir just until combined.
Stir in chopped nuts or chocolate chips (optional).
Pour the batter into the prepared pan.
Bake the bread until a toothpick inserted comes out clean, 50 to 60 minutes. Remove it from the oven and allow it to cool in the pan for 15 minutes before slicing and serving.