Making Meringue Cups
In a large mixing bowl, beat the egg whites, cream of tartar, vanilla and salt on medium speed until the egg white begin to increase in volume and soft peaks form. To test for soft peaks, lift the beaters from the whites, and the peaks of the egg white should curl down.
Add sugar, 1 tablespoon at a time, beating on high speed until stiff peaks form and sugar is dissolved. To test for stiff peaks of egg white should stand straight up; if you tilt the bowl, the whites should not slide around. Sugar is dissolved when the mixture feels silky-smooth between your fingers.
Line a baking sheet with parchment paper. Drop meringue into mounds on the paper. Using the back of a spoon, make an indentation in the center of each mound to form a 3-in. cup.
Bake as recipe direct. After drying in the oven for 1 hour, remove meringues to cool completely on baking sheet. Carefully remove meringues from paper and store in an airtight container at room temperature for up to 2 days.