IN A SMALL HEAVY SAUCEPAN, COMBINE THE CREAM AND BROWN SUGAR. BRING THE MIXTURE TO A BOIL OVER MEDIUM HIGH HEAT, WHISKING OCCASIONALLY, BRING TO A BOIL , WHISKING UNTIL SUGAR IS DISSOLVED.
REMOVE PAN FROM HEAT AND ADD CHOCOLATES, WHISKING UNTIL THEY ARE MELTED. WHISK IN THE BUTTER AND THE AMARETTO. CONTINUE TO WHISK UNTIL THE SAUCE IS SMOOTH. LET COOL SLIGHTLY.