Preheat oven to 375°F.
Butter a 2qt soufflé dish, coat with bread crumbs. Chill.
In a large metal bowl set over a pan of simmering water, heat milk until very hot and gradually add cornmeal, whisking constantly. (The whisking is important, cornmeal has a real tendency to get clumpy.)
Cook, stirring frequently, until thick and smooth, about 5 min.
Remove bowl from pan and stir in butter. Cool, stir in salt, sugar, egg yolks.
In a medium bowl, beat whites to stiff peaks. Fold into mixture. Pour into prepared pan.
Bake at 375°F until puffed and golden, about 40 min.