Make the meringue: Preheat the oven to 250˚ F. Line two rimmed baking sheets with parchment paper.
Add the egg whites, cream of tartar, and salt to the bowl of a standing mixer fitted with the whisk attachment. Beat on high speed until the mixture turns white and foamy, about 2 minutes. With the motor still running, slowly add in the sugar in a steady stream and beat until the mixture has quadrupled in size and is thick and glossy, about 5 to 6 more minutes. Add in the vanilla extract and beat until just combined. Alternatively this step can be done with a hand mixer.
Transfer the meringue to a piping bag fitted with a star-shaped piping tip. Pipe 3-inch long squiggles on the sheet tray, spaced at least 2 inches apart. Continue piping until the sheet trays are full.
Bake until the meringues are completely dry to the touch, about 50 minutes to 1 hour. Turn off the oven, crack open the door, and let the meringues sit for 20 minutes. The meringues should be crisp all the way through. If not using right away, store your meringues in an airtight container in the freezer, where it is cold and dry. They’ll stay crunchy for up to 3 weeks.