Add 1/2 cup aquafaba (chickpea liquid) to the bottom of a large mixing bowl with 1/8 tsp cream of tartar or 1/2 tsp lemon juice and beat for 7 minutes until it forms a stiff meringue.
Add 2 tsp of vanilla and beat again for another minute.
Slowly add powdered sugar until the desired sweetness is achieved.
Notes
How to reduce aquafaba to make it thickerIf you open a can of garbanzo beans or white beans and find that the liquid is clear and watery, you will need to reduce it down to achieve its full thickening power.To do this, simply pour the liquid into a saucepan and simmer it over medium-low heat uncovered for about 10 -15 minutes until the liquid has reduced to about 1/2. At this point, it will be cloudy and thicker. Allow it to cool to room temperature before beating.