Set dry ingredients aside and begin meringue. My stand mixer didn't work to make this because it couldn't reach the aquafaba at the bottom, but if yours is a newer model then it will probably work great to make this meringue. For me, the best thing to use is the whisk attachment on the hand mixer, but I have succeeded with the beater attachment too, it just doesn't whip as much air into it so they might take longer.
Anyway, start the meringue by combining cream of tartar and aquafaba in the bowl of your mixer, with the granulated sugar measured out near you. Start whipping aquafaba and cream of tartar for 1-3 minutes on a low setting (low on hand mixer, medium low on stand mixer) until it starts to get really foamy.
Increase the speed now to medium, and whip for 2-4 more minutes, this time until your meringue starts to get a ton more air into it and gets foamier, fluffier, and bigger, but even if it doesn't really do this go to the next step after 2-4 minutes.
Now increase the speed to high, and add a spoonful of sugar into the mixture, drizzling it in slowly and whipping it in. Wait at least 20 seconds before adding more, and continue like this for a while. Your meringue should be getting aerated and bigger, and if it isn't and you are using a hand mixer, turn the bowl and violently whip in circles for a while, which should hopefully make it start working. You can start adding the sugar faster now, and when you finish adding all of your sugar, keep mixing for 3-5 minutes. The whole whipping should take 10-14 minutes, and it will depend on what you use and how long it takes for you to add the sugar.
Turn off your mixer, and pull out the whisk. If there is a stiff peak at the top of your mixer, (there are some photos of stiff peaks above) You did it!!! Vegan meringue!!! If there is only soft peaks, whip a bit more until you have stiff ones. When this meringue is done, you should be able to turn the bowl upside down over your head without anything falling out. (Make sure you have stiff peaks though first.)