Finely chop the chocolate and melt over a warm water bath. Whip liqueur, cream and icing sugar until stiff. Halve the cream and quickly stir the dissolved chocolate into one half. Finely crumble the biscuits.
Cookie crumbs, except for something to sprinkle, liqueur cream and and chocolate cream in glasses. Sprinkle with remaining cookie crumbs and chill for at least 1 hour.