With the knife blade in a food processor bowl, add the chocolate and process until finely ground. Scald cream in a heavy saucepan or microwave until the milk skims. With the processor turning, pour the hot cream through the food chute in a slow, steady stream. Mix well. Add the butter, sugar and liqueur to the chocolate. Process until blended. Pour into a large mixing bowl, cover and chill until firm. Shape the chilled mixture into small balls, cover and chill. Melt the dipping chocolate in a crockery bowl in the microwave for approximately 1 minute, stirring frequently. Dip the balls in melted chocolate. Cool and refrigerate in an airtight container for up to four weeks. Makes about 10-dozen truffles.