Preheat the oven to 225°F. Line a cookie sheet with parchment paper. Do not grease the pan!

In the bowl of a hand mixer or electric mixer, using the whisk attachment, whip the egg whites with the cream of tartar on high speed just until soft peaks start to form (about 4-5 minutes).

Continue mixing, adding the sugar very slowly. Once all the sugar is mixed in, add the vanilla and salt; beat until stiff peaks form (about 6-7 minutes). Gently fold in the cocoa powder until just combined.

Using a piping bag with a large star tip or a ziplock bag with the corner cut off, pipe 1 ½-inch wide cookies, spacing 1 inch apart. Pipe the cookies by holding the piping bag vertically, ½ inch above the parchment paper. Gently squeeze the bag, while holding it in the same place, until the cookie is 1 ½-inches wide. Then release pressure and pull straight upwards. Sprinkle a few mini chocolate chips on top of each cookie.

Bake for 1 hour. Do not open the oven while the cookies are baking or they can deflate. Once 1 hour is up, turn off the oven and let them sit for at least 2 hours, leaving the oven door closed. Don’t open the door until you know the oven is completely cooled down. You can even let them sit overnight.

The cookies are sure to be done once they look completely dry and can be easily removed from the parchment paper without sticking. Serve and enjoy.