Separate the egg whites from the yolks. Thoroughly mix the yolks, sugar, milk and flour. Whisk the egg whites and add a pinch of salt and continuing whisking until stiff. You can use a hand held beater or stand mixer instead. Now, carefully fold the whites into the egg yolk mixture. Melt butter in a large pan and pour in the mixture and sprinkle in raisins. Let cook on one side for a few minutes, turn over and tear into pieces with a fork. Now let cooking finish (ideally in a buttered pan in a preheated oven.) (Be especially careful not to overcook the pancakes, otherwise they will dry out. Sprinkle with powdered sugar and serve with plum puree.