Double Brownies

In a mixing bowl, cream the butter and brown sugar; beat in eggs, vanilla and salt. Stir in flour and nuts. Spread into a greased 13-in. x 9-in. x 2-in. baking pan; set aside. For middle layer, cream butter and sugar; beat in eggs and salt. Stir in flour, cocoa and nuts. Spread over the bottom layer. Bake at 350 degrees F for 35-40 minutes or until a toothpick inserted near the center comes out clean. Cool. For icing, melt butter in a saucepan over medium heat. Stir in brown sugar and milk; bring to a boil. Remove from the heat. Cool just until warm; beat in confectioners' sugar until the icing is of spreading consistency. Spread over brownies. ');