Mix together sugar, 1 stick margarine, 4 eggs. Add in syrup, flour, vanilla, baking powder and nuts (optional). Place in greased 9x13 pan. Bake 350 degrees for 30 minutes. While brownies are baking, make frosting.
Frosting: In medium saucepan stir together 1 1/3 C sugar, 6 T margarine and milk. Bring to boil and boil 1 minute. Take off burner. Add chocolate chips. Cool some. When brownies cool,pour frosting over the top. Garnish with nuts if desired.