Melt unsweetened chocolate; let cool slightly. Beat Canadian Cream cheese, softened and vanilla extract until smooth. Gradually beat in icing sugar and brown sugar. Beat in melted chocolate. Stir in miniature marshmallows and 1-1/2 cups (375 mL) walnut pieces.
Press mixture into square 8-inch (20 cm) foil-lined pan. Cover and chill until set. Cut into squares.