This icing is not as hard as it sounds and it is absolutely the best caramel icing you will ever eat. Mine is a little runny when I put it on the cake, but it hardens, so you don't want to get it to hard before you frost cake.
To the browned sugar in skillet or pan, add water to make thin syrup. Don't panic, when you add the water mixture will become hard, just keep stirring. Stir in sugar, milk, butter and soda; boil briskly for 11-12 minutes, stirring often. Cook to a soft ball stage , cool a little and then beat until desired thickness. Add nuts and vanilla. Spread between layers and on top and sides.