Preheat oven to 350* line 2 cookie sheets with parchment paper, lightly coat with nonstick spray
In large bowl, whisk confectioners sugar, cocoa and salt. Beat egg whites till stiff fold in add vanilla and beat until smooth. fold in chocolate chips. let dough rest 5 min.
Drop dough by rounded tablespoons 2 in. apart onto cookie sheet. Bake 13 to 15 min. or until set and crackly. let cool on cookie sheet, 3 min. then transfere to wire rack to cool completely