Grease and flour two 8x4 bread loaf pans (or just spray them with nonstick cooking spray).*
In a medium bowl, stir together flour, cinnamon, baking powder, baking soda, and salt.
In the bowl of an electric mixture, beat eggs until they are light yellow and frothy. Add sour cream, oil, white and brown sugars, grated zucchini, bananas, and vanilla.
Slowly add dry ingredients to the wet ingredients and mix thoroughly to combine. Do not over mix.
Fold in walnuts.
Divide batter evenly between loaf pans.
Sprinkle loaves with raw sugar. (optional)
Bake in preheated oven for about 45-50 minutes, or until a toothpick inserted in the center comes out clean.
Allow to cool in the loaf pans for 15 minutes on a wire rack before removing. Allow to cool completely.
You can also use one large loaf pan and two small ones, or five small loaf pans, or (about) 24 muffin cups, or any combination that makes you happy. Just be sure to adjust cooking time to compensate for the smaller pans.
This website provides approximate nutrition information for convenience and as a courtesy only. You are solely responsible for ensuring that any nutritional information provided is accurate, complete, and useful.