ISO: Cake Icing - cooked, using evaporated milk

My mother was from East Texas and she made this cake icing recipe which I would love to have. It is difficult to describe and all I can remember about it was that she used Carnation Evaporated Milk and cooked it on the stove. She would pour it warm on a devil's food cake and it was soooo good. After the icing had cooled on the cake it would become a little hardened. I don't know if she used brown sugar or white and I do know she put vanilla in it.

With this very limited description would anyone possibly be able to come up with a recipe such as I have described?

Thanks so much!