Pre-heat the oven to 300°F (148°C). Line a cookie sheet with parchment paper.
In a large clean bowl, add the egg whites along with cream of tartar and vanilla extract. Using your hand mixer, beat the eggs on high speed until they are fluffed and form soft peaks.
Now add the sugar and beat it again on high speed until the meringue is glossy and has stiff peaks.
Sift the cocoa powder over the meringue and add the chocolate chips. Using a spatula, gently fold in the cocoa powder and the chocolate chips in the meringue. Do this gently; you don’t want to deflate the meringue.
With the help of two spoons place 12-14 mounds of the meringue on your prepared baking sheet. If you like, you can also pipe the meringue.
Let the cookies bake for 35-45 minutes or until the cookies have a crisp outside and release from the parchment paper easily. Once done, remove them from the oven and cool them on wire rack.
These cookies can be stored covered at room temperature for 3-4 days.
Notes
These cookies are crispy on outside and soft and gooey from inside. If you bake it longer they will get firmer at inside. If you prefer baking them longer lower the temperature to 250 degree F.