Blend sugar, butter and chocolate; add eggs one at a time until well blended. Mix in vanilla. Combine flour, baking powder & salt, mix and add to chocolate mixture a little at a time mixing well after each addition. Cover & chill 2 hours or overnight. Drop mixture by rounded tsp. into sugar coating lightly then shape into balls. Place on greased cookie sheet, 2 inches apart and flatten slightly. Bake at 350 degrees for 12 to 14 minutes and cool on wire rack.  (I don't have how many it makes but I would imagine a couple dozen.)