How often do you allow your child to eat cake?

My health conscious friend only allows her child to have cake during holidays like Easter, Christmas and his birthday. I've seen how hyper her little boy gets with some icing and cake in his system so I understand perfectly why she limits his cake intake to special occasions. She also said that at these special days/events, there are more adults around who can tend to the child's sudden energy burst so she does not feel too frazzled.