Preheat oven to 350 degrees. Prepare 2 8-inch loaf pans with cooking spray (or grease and flour).
In a large bowl, beat together the eggs, sugar, oil, sour cream, and vanilla. In a separate bowl, mix the flour, cinnamon, soda, salt, and baking powder. Add to the first mixture and stir until blended.
Fold in zucchini and walnuts, pour into the prepared pans. Bake for 40-45 minutes.
Allow the pans to stay in the pans for another 10 minutes, then turn the loaves out onto a rack.