There are a few good replacements for eggs in cookies. Aquafaba and flax eggs are two of the best. Aquafaba is the juice from a can of chickpeas, and flax "eggs" are made by combining ground flaxseeds with water. This recipe uses aquafaba. In general, 3 tablespoons of aquafaba equals one egg, while 2 tablespoons equals one egg white. If you plans to adapt a non-vegan recipe, don't forget you may need to play around with the leavener ratio. In this case, we increased the amount of baking powder.