Preheat the oven to 325 F. In a medium saucepan stir 2 cups of the milk into the cornmeal. Cook, stirring constantly, until the mixture is very thick and pulls away from the sides of the pan. Remove from the heat, stir in the remaining milk , butter, baking powder, sausage, cheese, salt, and pepper mixing well. Stir 1 cup of this hot mixture into the egg yolks, mix to combine , and return all to the sauce pan. Gently fold in the beaten egg whites. Pour into a greased 2 qt. casserole dish. Bake for 40 to 50 minutes.