* Tastes richer if real butter is used, but can use solid margarine if desired, NOT diet or soft margarine. ** Add vanilla flavoring instead of rum if preferred. Purchase a pound cake or prepare from mix following directions on package. For the frosting, combine butter, brown sugar, and milk in a saucepan. Bring to a full boil and add the confectioners sugar and rum or vanilla flavoring. With a whisk, beat mixture until smooth. Add a bit more milk if needed, to make a fairly thin sauce that will pour easily onto cake. Punch holes in cake with fork tines. Pour the warm sauce slowly over cake. ----