To replace one egg in a recipe, blend 1/4 cup tofu and add to your mixture.The tofu replacement works best in recipes that require a denser texture, such as cakes. To replace one egg, blend 1 tbsp. flax seed until it is finely ground. Add 1/4 cup cold water and blend until thick. It has a nutty flavor and provides a jelly-like texture to your baking that mimics the consistency of egg yolks. You can find flax seed in health food or grocery stores.