In a medium saucepan, melt the chocolate and butter over low heat. Stir in the all of the remaining ingredients, including a dash of salt.
Cook, stirring constantly, about 5 minutes or until the mixture is slightly thickened. Serve over your favorite ice cream or frozen yogurt. Refrigerate leftovers.
TO REHEAT: On a small saucepan, combine the sauce with a small amount of water. Heat slowly, stirring constantly, over low heat.