1. Preheat oven to 350 degrees. Place zucchini cubes, eggs, and oil in a blender. Blend at high speed until mixture is finely pureed - small green flecks will be visible. Add walnuts, and blend briefly to chop. Set aside.
2. In large bowl mix flour, sugar, cinnamon, baking powder, baking soda and salt. Add blended zucchini mixture. Stir just enough to moisten dry liquid. Fold in chocolate chips and vanilla.
3. Pour batter into two 9 x 5" bread pans that have been sprayed with Pam. Bake at 350 degress for 1 hour and 15 minutes, or until toothpick placed in center of loaf comes out clean. Cool 15 minutes, run knife around edges of pans, and remove loaves from pans. Continue cooling on wire racks.