Preheat oven to 350. Spray cookie sheet with nonstick spray. Mix brownie mix (dry), egg whites and yogurt. Drop by teaspoonful onto cookie sheet. Bake 10 to 11 minutes. Cool 1 to 2 minutes remove from cookie sheet. Cool completely. Frost with frosting.
Makes about 4 dozen.
1 cookie has 85 calories, 1 gram of fat, no cholestrol.