I found these in O, The Oprah Magazine. I think it was the December issue.
All you need is sweetened condensed milk, lots of chocolate, and a little heavy cream.
They make cute little gifts.
Just drop a cube (unwrapped, of course) into a saucepan with a mugful of milk. Heat until the chocolate has melted. For a really rich treat, substitute a little heavy cream for some of the milk.
This is my new favorite way to make Hot Chocolate. If only I had home made marshmallows too. (I could fix that with a little effort.)