Preheat the oven to 225℉. Line cookie sheets with parchment paper.
Beat egg whites in a stand mixer with the whisk attachment. As they foam, add salt, cream of tartar, and vanilla until soft peaks form.
4 Egg Whites , 1/4 teaspoon Cream of Tartar , 1/8 teaspoon Salt , 1 ¼ teaspoon Clear Vanilla
Gradually add sugar while continuing to whip until stiff peaks form, and the meringue is shiny, about 5 minutes. *See Note.
1 Cup Sugar
Next, test the meringue by rubbing a small bit of the mixture between your fingers, you shouldn’t feel the sugar, otherwise keep beating.
Using a large disposable piping bag, add a large star tip and transfer meringue to prepared piping bag and pipe onto prepared cookie sheet.
Bake at 225℉ for 1 hour. Do not open the oven! Leave the oven door closed and allow cookies to cool completely in the oven for 1-2 hours then remove.
Notes
If you're planning to add color, add the food gel at this point. Note that the cookies will brown and darken when baked when you add food coloring.Adapted from All Recipes