Bananas safely replace eggs whether you cook for someone who has egg allergies or follows a vegan diet. Eggs provide binding, leavening and moisture to baked goods. However, bananas mainly serve as moisture and binder, so you may need to add extra leavening for some baked goods. Bananas also add their flavor when used as an egg replacer, so only use them when the banana flavor complements the baked good.
Place 1/2 banana per egg in the bowl. Thoroughly mash the banana with a fork, until no large lumps remain.
Measure out 1/4 cup mashed banana per egg. You may have some banana left over or need to mash a little more, depending on the size of the bananas.
Mix the mashed banana into the rest of the wet ingredients.
Add 1/4 tsp. to 1/2 tsp. baking powder per egg in recipes where leavening is important, such as cakes and cookies. Mix the baking powder in with the other dry ingredients.
Add the lesser amount of baking powder when baking at high altitudes -- about 4,000 feet and higher.