Preheat your oven to 225°F (107°C). Line two large baking sheets with parchment paper.

In the clean, dry bowl of a stand mixer fitted with the whisk attachment, beat the room temperature egg whites and cream of tartar on medium speed until they become foamy and soft peaks form, about 2-3 minutes.

With the mixer running, add the granulated sugar one tablespoon at a time, waiting 30 seconds between each addition, until dissolved.

Increase to high speed and beat until meringue is stiff, glossy, and holds a sharp peak, 5-8 minutes. Beat in vanilla during the last minute.

Use a toothpick to paint 2-3 stripes of gel food coloring inside a piping bag fitted with a star tip.

Transfer meringue to the piping bag and pipe 1-inch wide kisses onto the baking sheets, about 1 inch apart.

Bake for 45-60 minutes until dry and firm. Turn off oven, crack door open, and cool inside for 1 hour.