I saw this on an episode of 'Come Dine with Me' the other day. The measures I have given are what I have tried and are approximate since none were given on the show. Feel free to add either more brown sugar or butter as per your taste. It is served along with a scoop or two of vanilla ice cream. I didn't have ice cream on hand so I had it just like that and quite liked the earthy flavour of the brown sugar sauce.