Peel apples. Cut them from their cores in wedge-shaped slices. Put a chunk of butter into a 10-inch iron, enamel, or ovenware skillet that is also flame-proof. Add apple slices and sauté about 15 minutes, or until soft. Sprinkle with salt and 4tablespoons of sugar. Remove from heat. Add vanilla and cinnamon to the Calvados. Pour over the apples. Stir and set aside to cool.
Preheat oven to 400 degrees. Fifteen minutes before serving the dessert, mix the batter. Put flour, baking powder, and salt into a small mixing bowl. Pour milk into a measuring cup, add the yolks to it, and beat together.
Beat the whites until they start to stiffen. Gradually add 2tablespoons of sugar and beat until stiff.
Stir the milk-yolk combination into the flour. Beat out the lumps. Stir in the stiffly beaten egg whites. Mix well. Pour over the cooled apples in the skillet. Sprinkle with sugar and bake about 12 minutes, or until lightly browned and puffed to the top of the skillet.
Stir lemon juice into the crème. Dilute it with whipping cream. Pour into a serving dish. When the pancake is done, remove it from the oven and invert it onto a serving plate. The apples are on top and the cake on the bottom. (It will fall, like a soufflé.) Sprinkle apples with a lot of sugar, cut the pancake into wedges, and serve with the sour cream. Should serve 6, but 3 will eat the whole pancake