Combine cookie crumbs and quarter cup margarine; press into bottom of 23 cm springform pan. Combine cream cheese and milk, mixing at medium speed on electric mixer until well blended. Add eggs, one at a time, mixing well after each addition. Blend in chocolate and vanilla; pour over crust. Bake at 150ºC or 1 hour and 10 minutes. Loosen cake from rim of pan; cool before removing rim of pan. Beat one third cup margarine and sugar until light and fluffy. Add chocolate and liqueur, mixing well. Frost top and sides of cheesecake. Chill.