For a 12 X 8.5 inch baking pan.
Preheat oven to a medium temperature of 330 F.
Place the cornmeal, butter (cut into cubes), sugar and a pinch of salt in a heatproof bowl. Bring the milk to a boil and pour over the bowl. Stir the ingredients and let it rest for 5 minutes.
Add the soft cheese, sour cream, zest, vanilla and egg yolks and mix together. Stir in the sifted flour. In a clean mixer bowl, whisk the egg whites and gradually add the sugar. Whisk till soft peeks are formed and fold into the cheese mixture.
Pour the mixture into a greased 8.5 X 12 inch baking pan or little silicon molds. Bake for 45 minutes or a lot less if you're using muffin pan.
Serve warm (not hot !) with sour cream and Sour Cherry or strawberry Jam.