Roughly chop the chocolate and melt over the water bath. Line a muffin tin with six molds and pour a tablespoon of chocolate into each mold. Place the muffin tin with the chocolate in the freezer for 10 minutes. Then take it out again and put 1/2 tablespoon peanut butter in the middle of the chocolate. Return the tray to the freezer for 10 minutes. Spread the rest of the chocolate on top and place in the freezer for 20 minutes to set.