Preheat the oven to 200 degrees F and line a baking sheet with parchment paper.
Place the egg whites in a clean mixing bowl and add the cream of tartar.
Beat the mixture on medium speed until soft peaks form.
Gradually add the sugar while beating on high speed until stiff, glossy peaks form.
Mix in the vanilla extract on low speed until 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 2 hours, then turn off the oven and let the cookies cool inside with the door closed.