4 ounces unsweetened chocolate
Preheat oven to 350°F. Line 13×9-inch baking pan with foil, with ends of foil extending over sides of pan. Grease foil.
Microwave chocolate and butter in large microwaveable bowl on HIGH 2 min. or until butter is melted. Stir until chocolate is completely melted. Stir in sugar. Blend in eggs and vanilla. Add flour and salt; mix well. Spread into prepared pan.
Bake 30 to 35 minute or until toothpick inserted in center comes out with fudgy crumbs. (Do not overbake.) Cool in pan on wire rack. Remove brownies from pan, using foil handles. Cool brownies, then cut them into 3/4- to 1-inch squares.