Preheat the oven to 350ºF.

Line a 9-inch loaf pan with parchment paper then grease the parchment paper with cooking spray.

In a large bowl, whisk together the flour, sugar, baking soda and salt.

In a separate medium bowl, whisk together the mashed bananas, buttermilk, eggs, melted butter and vanilla. Stir the banana mixture into the dry ingredients.

Shred the zucchini on the small holes on a box grater. Measure out 1 1/2 cups of shredded zucchini then squeeze it with your hands over the sink to remove as much excess liquid as possible. Fold the zucchini into the batter then scrape the batter into the prepared loaf pan.

Bake the bread for 50 to 60 minutes until a toothpick inserted comes out clean. Transfer the pan to a cooling rack to cool then lift the loaf out of the pan, slice and serve.

Squeezing the excess moisture out of the zucchini ensures your bread won’t sink in the center.

Extra-ripe bananas are the key to the most moist, flavorful banana bread. Don't be afraid to let bananas turn completely brown before using them for banana bread. If you don't have extra-ripe bananas, check out my video for how to ripen bananas in 15 minutes.

If you don't have buttermilk on hand, you can make a quick version using whole milk and lemon juice or white vinegar. Add 1 tablespoon of lemon juice or white vinegar to a liquid measuring cup, and then pour in the milk until it reaches the 1-cup mark. Let the mixture sit for 5 minutes, then use 1/4 cup for this recipe and save the rest for another use.