Spread the sugar on a clean baking sheet and heat the sugar in the oven for 8-10 minutes until you can see the sugar start to dissolve around the edges.
When you remove the sugar from the oven, turn the heat down to 225.
A few minutes before the sugar is finished, place the egg whites and the cream of tartar in the bowl of a stand mixer.
Beat the egg whites on high until they begin to froth and then, while the mixer is still going, begin gradually adding the sugar.
Once all the sugar has been added, add the vanilla extract and continuing beating the egg whites until they form stiff peaks and are glossy. This could take as long as ten minutes.
Line two baking sheets with parchment paper or Silpat baking mats.
Spoon large dollops of meringue onto the baking sheet - six on each. Divide the meringue evenly between the twelve cookies.
Bake each tray at 225 for two hours until firm on the outside and cooked through but still chewy on the inside. If yours are not done, you can turn off the heat and leave them in the oven for longer.
Store meringues in an airtight container. They will last for weeks.
Recipe by West of the Loop at https://www.westoftheloop.com/2014/03/23/french-patisserie-meringues/