Place the chickpea liquid (aquafaba) and cream of tartar into the bowl of an electric mixer.
Start at slow speed and whip until foamy.
Then gradually increase speed until white and glossy and stiff peaks start to form.
Add the sugar in slowly while whipping at fast speed.
Add in the vanilla.
Keep whipping until glossy stiff peaks form.
Preheat your oven to 250°F (121°C).
Line a baking tray with parchment paper.
Pipe the meringue mix into cookie shapes onto the parchment lined tray. Alternatively you can spoon it out, but I found piping to be much easier.
Place into the oven and bake for 45 minutes. After 45 minutes, switch off the oven but DON'T OPEN IT (excuse the caps, but this part is very important). Leave the oven off, but don't open it for one hour. Time it.
After the meringues have baked for 45 minutes and then sat in the oven for a further 60 minutes without opening the oven, remove them from the oven.
They should be airy crispy perfection! If the weather is at all hot or humid, put them in an airtight container and store them in the fridge for the most long lasting results.