Add 5 very fresh large egg whites to 1¼ glasses thick raspberry, wild straw-berry, or black currant jam. There should be more berries than syrup. Beat with a spoon in one direction for at least an hour, until the mixture turns almost white and is very thick, or until a spoon can stand upright in it. Transfer to a deep platter and set in a cold place. When the Main course is being served, sprinkle the soufflé with 1 spoon sugar, and bake it in a fairly hot oven. As soon as the soufflé rises and browns, serve it immediately at the table with cream.
This soufflé is so good that it does not fall as others sometimes do when prepared as indicated. It is more substantial and tastier, although it requires more work.