In the bowl of a stand mixer or a large mixing bowl, combine the aquafaba and cream of tartar.
Beat on high speed for 5 to 6 minutes, until the mixture forms stiff, white peaks.
With the mixer still running, gradually add the sugar, about ¼ cup at a time.
Continue to beat for another 3 to 4 minutes until the meringue becomes thick, glossy, and holds firm peaks.
Gently beat in the vanilla extract until just combined.
Use your meringue immediately. For cookies, scoop or pipe onto a parchment-lined baking sheet and bake at 200°F / 95°C for 1 to 1. 5 hours. Alternatively, use it as a topping for pies and other desserts.
Add the sugar very gradually. Dumping it in all at once can deflate the air you've worked so hard to incorporate, resulting in a less stable meringue.
