Peppermint Meringue Cookies

Ingredients
Method
Place racks in upper and lower thirds of oven; preheat to 225°. Place 5 large egg whites, room temperature, in the bowl of a stand mixer fitted with the whisk attachment. Sprinkle ¼ tsp. cream of tartar and ¼ tsp. Diamond Crystal or Morton kosher salt over and let sit 5 minutes.
Meanwhile, sift ¾ cup (150 g) granulated sugar and ¾ cup (83 g) powdered sugar into a medium bowl and whisk to combine.
Beat egg white mixture on medium speed until foamy, 30–60 seconds. With motor running, add sugar mixture 1 Tbsp. at a time, incorporating completely before adding more and scraping down sides of bowl as needed between additions, 6–8 minutes total. Increase speed to high and beat meringue until glossy stiff peaks form (it should look billowy), about 2 minutes. (Stiff peaks are important here as the meringue will deflate slightly when piped; the cream of tartar will prevent overbeating). Reduce speed to medium, add ½ tsp. vanilla extract and ¼ tsp. peppermint extract, and beat until just incorporated.
Place pastry bag fitted with tip into a tall glass or vase and fold top of bag over rim of glass to hold it in place. Using brush, paint 4 thin stripes of food coloring up the inside of bag, spacing evenly apart. Fill bag with meringue, then bring sides together and twist to close. Dab a little meringue in each corner of a baking sheet and line with parchment paper; lightly press meringue dabs to adhere parchment to baking sheet. Holding pastry bag vertically about 1" above baking sheet, working in an upward motion and twisting at the base to create a swirled shape, pipe meringue to make a 2"-wide star. Repeat to fill baking sheet, spacing meringues about 1” apart. Repeat process with another pastry bag and baking sheet.
Bake meringues until crisp on the outside and shiny (but not sticky or tacky), 2 hours to 2 hours and 45 minutes. To check if they are ready, lift a meringue off the baking sheet: it should be light, lift off the baking sheet cleanly, and sound hollow when tapped on the bottom. If meringues are not done after 2 hours, keep baking, checking every 20 minutes.
Turn off oven and leave door slightly ajar (prop open with a wooden spoon if needed). Let meringues cool in oven at least 1 hour and up to 12 hours. Do Ahead: Meringues can be baked 10 days ahead. Store in an airtight container at room temperature. If meringues soften, re-crisp in a 225° oven 10–15 minutes.