Grandma Nolan's Angels' Delight

No idea of the year, but we found this in Grandma's recipe box and mom remembers it being very delicious.

• 6 oz bag of chocolate chips
• 1 square unsweetened chocolate
• 3 T powdered sugar
• 4 eggs, separated (whites beaten stiff but not dry)
  
• 1 C whipping cream, whipped
  
• 1/2 C nuts, chopped
• 1/2 lb Angel Food cake

Butter a 9x13" pan and break cake into it. Melt chocolate chips & chocolate square in top of double boiler. Add sugar and egg yolks one at a time; beat after each one. Add whipped cream, then fold in egg whites. Add nuts. Pour mixture over cake and chill at least 8 hours in the refrigerator. May be served with whipped cream and a cherry.