Preheat the oven to 200 degrees Fahrenheit and line a baking sheet with parchment paper.

Place the egg whites and cream of tartar in a mixing bowl. Beat with an electric mixer on medium speed until soft peaks form.

Add the sugar one tablespoon at a time while continuing to beat. Keep mixing until stiff peaks form and the mixture looks glossy.

Mix in the vanilla extract on low speed until just combined.

Spoon the meringue into a piping bag fitted with a round tip. Pipe ghost shapes onto the prepared baking sheet, leaving space between each one.

Press two mini chocolate chips into the top of each ghost to form eyes.

Bake for 90 minutes. Turn off the oven and leave the cookies inside to cool completely with the door closed.