Line an 8-inch square pan with foil. Melt butter in a glass bowl
on HIGH, 1 minute.
Stir in sugar and milk. Cook on HIGH for
8 minutes, stirring every 3 minutes. Add marshmallows and chocolate;
stir and reheat until smooth.
Stir in nuts and liqueur.
Pour into prepared pan. Chill until firm. Cut into pieces.
