Preheat the oven to 225 degrees F., and adjust two racks so that they are in the upper-middle and lower-middle position.

Line two baking sheets with parchment paper, and set aside.

In a small bowl, combine the sugar, cornstarch, and salt, and whisk to combine.

Whip the egg whites, vanilla, and cream of tartar together with an electric mixer on medium-low speed, until the mixture is foamy, about 1 minute.

Increase the mixer speed to medium-high, and whip until the whites are soft and “billowy.”

Gradually add the sugar mixture while the mixer is running, and whip until the whites are glossy and form stiff peaks, 1 to 3 minutes.

Fold in chocolate chips.

Use a spoon or a pastry bag fitted with a plain tip to make 1 1/4-inch wide meringue kisses on the prepared baking sheets, spaced about an inch apart.

Bake the meringue cookies for 1 hour. Turn off the oven, and let the meringues sit in the oven for an additional 1 hour (or 2 hours if in humid or rainy conditions). Remove the cookies from the oven, and let them cool before serving, about 10 minutes.

Keep meringues crispy by storing extras in an airtight container if you live in a humid area.