Pre-heat your oven to 220ºF and line a baking sheet with parchment paper
Bring 2 inches of water to a simmer in a pot. Place a clean stainless steel mixing bowl over the water. It shouldn't touch the water.
Combine your egg whites and sugar and whisk to combine. Occasionally whisk as it's heating to distribute the heat and dissolve the sugar.
Once your egg whites are at 110ºF (or when you don't feel any grains of sugar between your fingers) you're read to whip
Place the bowl on your stand mixer with the whisk attachment. Whisk on med for one minute, add in cream of tartar, salt and flavoring.
Bump up to high and let whip until you reach STIFF peaks.
Now you are ready to pipe your meringue onto the baking sheet into flowers! (see video for more details on piping)
Bake for 2 hours, then turn off the oven but do not take out the cookies. Let them sit in the oven until they are completely cold. I leave mine in overnight.
Cookies can be stored in a ziplock bag unrefrigerated for up to two weeks.