Beat the egg whites in a clean bowl until soft peaks form. Lift your beater or whisk straight up: the egg whites will form soft mounds rather than a sharp peak. Beat the egg yolks in a separate bowl until smooth; mix in the milk, sugar, salt, flour, and raisins until just moistened. Fold in the egg whites.
Melt the butter in a large skillet over medium heat. Pour the batter into the skillet and cook until golden brown; flip and cook until set on the other side, about 1 minute. Tear the kaiserschmarren into pieces using two forks and continue cooking until golden brown, about 2 minutes. Sprinkle with confectioners' sugar to garnish and serve with applesauce.