Aquafaba. Can be bought readymade but is also a by-product of cooking dried chickpeas. After soaking chickpeas in water for a night discard the soaking water. Bring fresh water to boil and cook the chickpeas for 1/2 an hour or so. Collect the cooking water. You can even also freeze it for later use. It's important to bring it to room temperature before using it in baking. Can bring a good amount of fluffyness to your doughs.