Cream butter and sugar in large bowl. Combine the eggs and milk in small bowl. In another small bowl, combine flour, cornmeal, baking powder and salt in small bowl; add to creamed mixture alternately with egg mixture.
Pour into a greased 33x23x5 cm cake pan. Bake at 200 C for 22-27 minutes or until a toothpick inserted near the center comes out clean. Cut into squares; serve warm.