Banana Brownies

In a bowl, combine butter, sugar and cocoa. Stir in eggs, milk and vanilla. Blend in flour, baking powder and salt. Stir in bananas and nuts. , Pour into a greased 9-in. square baking pan. Bake at 350° until a toothpick comes out with moist crumbs, 40-45 minutes. Cool on a wire rack. Just before serving, dust with confectioners' sugar if desired.