In a medium-sized bowl, add the unsweetened cocoa powder, sifted powdered sugar, and salt. Whisk it until well-combined.
In another bowl, add 2 egg whites and vanilla extract. Whip it until soft peaks form. Gradually add the powdered sugar mixture and fold it in the meringue mixture.
Add the chocolate chunks to the mixture and mix well.
Scoop the mixture on your cookie sheet and bake for 15 minutes at 350F.