Preheat the oven to 350 degrees. Lightly butter a 1 1/2-quart souffle dish.
Combine the cornmeal, salt, and sugar and stir slowly into scalded milk in saucepan. Over low heat, blend in butter. Remove saucepan from heat and beat in egg yolks and baking powder. Let cool.
Beat egg whites with a pinch of salt until stiff. Gently fold into cornmeal mixture. Pour batter into prepared mold and bake until puffed and golden, 30 to 35 minutes. Serve immediately.