1Heat oven to 350°. Grease and flour rectangular pan, 13x9x2 inches. Stir together granulated sugar, baking mix, 1/4 cup margarine, 2 teaspoons vanilla, 4 squares melted chocolate and the eggs in medium bowl until moistened. Spread in pan. Bake 30 to 35 minutes or until edges begin to pull away from sides of pan; cool.
2Stir together powdered sugar, 1/2 cup margarine, the milk and 2 teaspoons vanilla in medium bowl until smooth. Spread over brownies; refrigerate until firm. Heat 3 squares chocolate over low heat until melted; cool slightly. Spread evenly over frosted brownies. Refrigerate until set. Cut into about 1 1/2x1-inch brownies. Refrigerate any remaining brownies.