Mix flour and milk together. Add salt. Stir in egg yolks, ¼ cup butter and raisins (if using). Beat egg whites in a separate bowl with the sugar until peaks form. Melt ½ cup butter in a 12 inch skillet that can be placed in the oven. Add egg whites to the flour mixture and pour batter into pan. Bake at 375 degrees F for 18 minutes (I baked mine for 20 minutes, but it was 2 minutes too long). Sprinkle with powdered sugar and serve with plum sauce.
Recipe by This Week for Dinner at https://thisweekfordinner.com/kaiserschmarrn-aka-emperors-pancakes-take-one/