In baking I almost always use Ener-G Egg Replacer which you can buy at almost any health food store or grocery stores. There are several other similar brands, but this is my favorite.
Tofu: Tofu is great for egg substitutions in recipes that call for a lot of eggs, like quiches or custards. To replace one egg in a recipe, purée 1/4 cup soft tofu. It is important to keep in mind that although tofu doesn’t fluff up like eggs, it does create a texture that is perfect for “eggy” dishes.
Tofu is also a great substitute for eggs in egg-less egg salads and even scrambled eggs.
In Desserts and Sweet, Baked Goods: Try substituting one banana or 1/4 cup applesauce for each egg called for in a recipe for sweet, baked desserts. These will add some flavor to the recipe, so make sure bananas or apples are compatible with the other flavors in the dessert.
Other Egg Replacement Options
• 1 egg = 2 Tbsp. potato starch
• 1 egg = 1/4 cup mashed potatoes
• 1 egg = 1/4 cup canned pumpkin or squash
• 1 egg = 1/4 cup puréed prunes
• 1 egg = 2 Tbsp. water + 1 Tbsp. oil + 2 tsp. baking powder
• 1 egg = 1 Tbsp. ground flax seed simmered in 3 Tbsp. water
• 1 egg white = 1 Tbsp. plain agar powder dissolved in 1 Tbsp. water, whipped, chilled, and whipped again
Egg Replacement Tips
• If a recipe calls for three or more eggs, it is important to choose a replacer that will perform the same function (i.e., binding or leavening).
• Trying to replicate airy baked goods that call for a lot of eggs, such as angel food cake, can be very difficult. Instead, look for a recipe with a similar taste but fewer eggs, which will be easier to replicate.
• When adding tofu to a recipe as an egg replacer, be sure to purée it first to avoid chunks in the finished product.
• Be sure to use plain tofu, not seasoned or baked, as a replacer.
• Powdered egg replacers cannot be used to create egg recipes such as scrambles or omelets. Tofu is the perfect substitute for eggs in these applications.
• If you want a lighter texture and you’re using fruit purées as an egg substitute, add an extra 1/2 tsp. baking powder. Fruit purées tend to make the final product denser than the original recipe.
• If you’re looking for an egg replacer that binds, try adding 2 to 3 Tbsp. of any of the following for each egg: tomato paste, potato starch, arrowroot powder, whole wheat flour, mashed potatoes, mashed sweet potatoes, instant potato flakes, or 1/4 cup tofu puréed with 1 Tbsp. flour.source: VegCooking