Heat your oven to 350 degrees and line two cookie sheets with parchment paper.
Whisk the cocoa powder and sugar together. Add in the egg white, vanilla and salt and whisk until well combined and thick. Finally, fold in the chocolate.
Use lightly heaping cookie scoops to place onto the pan, leaving some room between each.
Bake until the top is set and crackly, about 14-15 minutes.