3 C powdered sugar
2/3 C cocoa powder
1/4 t salt
Mix in one at a time, just until moistened to a brownie batter consistency:
2-4 large egg whites (it took me 3 lg egg whites)
1 t vanilla
Spoon or scoop onto a lightly greased piece of parchment paper that's on a baking sheet.
Bake at 350° for 14 minutes. Remove parchment paper with cookies still on them directly onto a cooling rack until completely cool. Peel paper away from cookies carefully.