Heat oven to 350 deg F. Grease 23 cm square baking pan. In medium saucepan, combine sugar, evaporated milk and butter. Cook over medium heat, stirring constantly, until mixture boils; remove from heat. Add chocolate, stirring until melted; beat in eggs and vanilla. Stir in flour, baking soda, salt and nuts, if desired, until well blended. Pour into prepared pan. Bake 30 to 35 minutes or until brownies just begin to pull away from sides of pan. Cool completely in pan on wire rack. Cut into squares. About 16 brownies. -Rec.food.recipes is moderated; only recipes and recipe requests are accepted for posting. Please read the "Posting Guidelines" article. Recipes/requests go to recipes@rt66.com; questions/comments go to tfdpress@acpub.duke.edu. Please allow several days for your submission to appear.