Heat oven to 375°F. Grease 15x10x1-inch baking pan. In large bowl, combine 2 cups powdered sugar, 1/2 cup margarine, 1/4 cup brandy and eggs; mix well.
Lightly spoon flour into measuring cup; level off. With spoon, stir in all remaining bar ingredients until well mixed. Press mixture evenly in greased pan.
Bake at 375°F. for 15 to 25 minutes or until light golden brown. Cool 1 hour or until completely cooled.
In small bowl, combine all glaze ingredients, adding enough brandy for desired drizzling consistency; beat until smooth. Drizzle glaze over bars. Let stand until set. Cut into bars.