Preheat oven to 350 degree F. Lightly coat the bottoms of 4 5-inch loaf pans with cooking spray; set aside.
In a large bowl combine flours, sugars, soda, cinnamon, salt, and baking powder; set aside. In a separate bowl combine eggs, oil, and vanilla and mix well. Add to flour mixture and stir until combined. Gently stir in the zucchini and then the blueberries.
Spoon batter into prepared pans and sprinkle with turbinado sugar, if desired. Bake about 40 minutes or until golden brown and a toothpick inserted in the center of each comes out clean. Allow to cool in pan 10 minutes before removing. Serve warm or cool completely before slicing.
You can keep the bread in an airtight container up to three days or freeze it for up to three months. Frozen slices can go right into the toaster.