Harshly beat eggs and sugar together in wooden mixing bowl. Lightly stir in 2 cups milk and salt. Gradually stir in cornmeal, flour, and baking powder. Make certain everything is well blended. Now melt butter in cast-iron skillet. Turn skillet so as to grease sides. Pour creamy batter from mixing bowl into skillet. Smooth over top. Hold other cup of milk about 6 inches above skillet and slowly pour over top of batter in circular motion. Do not stir! Carefully place skillet in oven at 400 degrees. Bake 30 minutes. When spider cake is done, it will have streak of tasty custard running throughout. Serve hot with plenty of butter.