AUNT WINT’S CHOCOLATE  SAUCE - or THE Chocolate Sauce
Mom

5    squares baking chocolate
½   cup melted butter
2 ½  cups powdered sugar
2/3 cup evaporated milk

  

In a double boiler mix butter and sugar.  Add milk and mix thoroughly.  Cook over hot, not boiling, water ½ hour without stirring.  Then beat.  I leave this on the stove in the double boiler to reheat as needed, just as mother did.