Opera Cake is a vegetarian dessert. This recipe covers 7% of your daily requirements of vitamins and minerals. One portion of this dish contains about 10g of protein, 41g of fat, and a total of 769 calories. This recipe serves 4. A mixture of vanillan extract, milk, powdered sugar, and a handful of other ingredients are all it takes to make this recipe so delicious. From preparation to the plate, this recipe takes about 45 minutes.