Preheat your oven to 200 degrees Fahrenheit (about 93 degrees Celsius).
Ensure your mixing bowl is completely clean and dry.
Beat the egg whites at medium speed until foamy.
Add the cream of tartar and salt, and beat at medium-high speed until soft peaks form.
Gradually add the sweetener, one tablespoon at a time, mixing until stiff peaks form.
If desired, separate the meringue and add color or flavoring.
Pipe the meringue onto a parchment-lined baking sheet.
Bake for 40-50 minutes or until dry to the touch.
Turn off the oven and leave the cookies inside for 1-2 hours to dry completely.
Alternatively, leave them in the oven overnight.
