Use this recipe to top our Hermit Bars.
Combine brown sugar, milk, and butter in a medium saucepan. Stir over medium heat until the butter has melted and sugar has dissolved. Remove from heat, and whisk in vanilla and confectioners' sugar. If the icing is too thick to drizzle, stir in a little more milk. If it is too thin, add a little more confectioners' sugar. Let cool slightly before using.