Make flax eggs by stirring together flaxseed and water in a small cup. Let sit for a few minutes.
Combine flour, baking powder, baking soda, cinnamon and allspice in a large mixing bowl.
Place shredded zucchini, dates and vanilla extract in a food processor fitted with an "S" blade. Blend for 1-2 minutes, stopping to scrape down the sides as needed. Small pieces may remain, make sure all large pieces have been processed.
Pour zucchini mix and flax eggs into dry mixture as well as any add-ins (goji berries or walnuts) and stir until thoroughly combined.
Pour dough into a non-stick or lightly greased 9x5 inch bread pan.
Bake for 50 minutes, or until a toothpick or knife pushed into the center comes out clean.
If you don't have allspice, substitute 1/4 tsp ground nutmeg and 1/4 tsp ground cloves. Another options is simply increasing the cinnamon by 1/2 tsp.