Preheat oven to 350. Lightly grease a 9x13-inch pan.
In the bowl of a stand mixer (or using a handheld mixer) cream butter and sugar until light and fluffy. Add eggs and beat until combined.
In a separate bowl mix flour, cornmeal, baking powder and salt together. Add dry ingredients alternately with milk.
Pour batter into prepared pan and bake for 30-40 minutes or until the edges are slightly browned and a toothpick inserted into the center comes out clean.