Recipe from The Cafe Sucre Farine~
3 cups powdered sugar
1/2 cup plus 3 tablespoons unsweetened cocoa powder
1/4 teaspoon salt
2 1/2 cups chocolate chips
4 egg whites
1 tablespoon vanilla
Preheat oven to 350º. Line baking sheets with parchment and spray with non stick cooking spray.
Mix sugar, cocoa and salt in a bowl. Stir in chocolate chips. Add egg whites and vanilla, and mix till just moistened. Do not over-mix batter.
Drop by teaspoonfuls onto prepared baking sheets. Bake till the tops are slightly cracked and glossy, about 15 minutes. Cool only briefly before moving to a cooling rack. Cookies are fragile, but they will stick to parchment if not removed shortly after baking.