Preheat your oven to 225°F and line two baking sheets with parchment paper.
Put the egg whites, cream of tartar, and salt in a mixing bowl. Beat with a mixer on low until foamy. Add the sugar, 1 to 1 ½ tablespoon at a time, beating after each addition. Turn the mixer up to high and beat until stiff glossy peaks form, but do not overbeat.
Sift the cocoa powder over top and sprinkle on the chocolate chips, if using. Gently fold the ingredients in.
Dollop or pipe the meringue mixture onto your prepared baking sheets.
Bake for 30 minutes with one pan on the bottom rack and one pan on the second rack from top. After 30 minutes, rotate the pans and bake an additional 30 minutes or until dry to the touch. Turn the off oven, and let the cookies cool in the oven for 30 minutes.
Carefully remove the cookies to wire racks to cool completely.
Store the meringues in an airtight container at room temperature for up to 2 weeks (if you don’t eat them all).