- In large bowl, beat granulated sugar, 1/2 cup butter, the buttermilk, vanilla, egg and 2 ounces melted chocolate with electric mixer on medium speed, or mix with spoon. Stir in flour, baking soda and salt.
- On cookie sheet, drop dough by rounded tablespoonfuls about 2 inches apart.
- Bake 8 to 10 minutes or until almost no indentation remains when touched in center. Immediately remove from cookie sheet to cooling rack. Cool completely, about 30 minutes.
- In 2-quart saucepan, melt 2 ounces chocolate and 2 tablespoons butter over low heat, stirring occasionally; remove from heat. Stir in powdered sugar and hot water until smooth. (If frosting is too thick, add more water, 1 teaspoon at a time. If frosting is too thin, add more powdered sugar, 1 tablespoon at a time.) Spread over cookies.