Combine with Lemon Marshmallows and shortbread cookies to create our Lemon-Meringue Cookie Kebabs.
Preheat oven to 200 degrees. Lightly coat a parchment-lined baking sheet with cooking spray. Whisk egg whites and sugar in a heatproof mixer bowl set over a pan of simmering water until sugar dissolves and mixture is warm. Place bowl on mixer stand, add cream of tartar, and whisk on high until mixture is cooled, about 10 minutes.
Transfer to a pastry bag with 1/4-inch star tip (such as Ateco No. 822). Pipe kisses on sheet, 1 inch apart. Bake until firm and easily removed, 1 1/2 to 2 hours. If using kisses for cookie kebabs, immediately make the hole in the meringue by gently working a clean skewer through the kiss from the bottom. Let cool. Store airtight until ready to assemble; they will stay fresh for about a week in dry weather, far less in humid weather.