Flax eggs are a great substitute for eggs in vegan baking, for people with egg allergies, to add more fibre to your baking or if you simply run out of eggs. They are easily substituted in baking recipes like pancakes, muffins, and cookies.
Baked goods made with flax eggs are slightly gummier and chewier than those that use eggs, and the volume might be slightly decreased. As the texture of the baked goods will be different, it may be necessary to test the recipe first to determine if it meets your expectations.
Source: Canadianfoodfocus, healthyflax