Mix the rum and raisins in a bowl and leave for 1 hour to soak. Then chocolate milk and the butter is heated on the steam bath (put in a fireproof container, which put on a pot of water on the stove, and the court with chocolate should not touch the water, but only heated steam). Stir constantly until the chocolate is melted and a few minutes later, without being removed from the prana bath, chocolate mixture should become smooth and shiny. Add the raisins with the rum and stir again. The mixture is poured into the littered with baking paper square baking dish with sides 20 cm and smoothed top. Allow to cool at room temperature for a while and then placed for several hours in a refrigerator to set. Ready, cut into squares and serve.