Ian had a sweet tooth tonight and decided to make a batch of chocolate chip cookies. He read through the recipe and thought we had all the ingredients, but when he double checked (after the butter and sugar were creamed, etc.) he discovered we were out of eggs. No problem, I said--for each egg, substitute one tablespoon of flax and three tablespoons of water. That was verified by the flax packaging. So he did.
The cookies were beautiful and smelled lovely, but they tasted distinctly of flax. Not a pleasant bite when you're expecting something sweet. I've substituted flax for eggs in many recipes, mostly muffins, and it's been fine. Until now.
When making cookies, do not substitute flax for eggs. Unless you're vegan and you're used to that kind of thing. Even so, I would up the vanilla and sugar to mask the flavor. Yuck.