In a large bowl, cream shortening and brown sugar until light and fluffy. Beat in corn syrup and vanilla. Add eggs, one at a time, beating well after each addition. Combine the flour, cocoa and salt; gradually add to creamed mixture and mix well.
Spread into a greased 15x10x1-in. baking pan. Bake at 350° for 20-25 minutes or until a toothpick inserted in the center comes out clean. Cool on a wire rack.
In a large heavy saucepan, cook butter over medium heat for 5-7 minutes or until golden brown. Pour into a small bowl; beat in the confectioners’ sugar, vanilla and enough milk until frosting reaches spreading consistency.
Frost cooled brownies. Cover and refrigerate until firm, about 1 hour, before cutting.