1.Preheat oven to 160ºC.
2.Process macaroons and biscuits until fine. Add butter, process until combined. Press mixture over base and side of 26cm springform pan. Place pan on oven tray; refrigerate 30 minutes.
3.Meanwhile, make filling: Beat cream cheese, sugar, sour cream, liqueur, coconut milk, coconut and cornflour in medium bowl with electric mixer until smooth.
4.Beat in eggs, one at a time. Pour into pan over prepared base.
5.Bake cheesecake about 1 hour. Cool in oven with door ajar. Refrigerate cheesecake 3 hours or overnight.
6.When ready to serve, make glaze: Stir chocolate and unsalted butter in small saucepan over low heat until smooth. Refrigerate until mixture is spreadable.
7.Spread glaze over cheesecake; stand for 20 minutes before serving.