In large bowl, combine chocolate wafer crumbs and butter. Pat fimly into 23 cm springform pan, covering bottom and 6 cm up sides. Chill. Preheat oven to 160ºC . Combine over hot (not boiling) water, chocolate chips and heavy cream. Stir until morsels are melted and mixture is smooth. Set aside. In large bowl, combine cream cheese and sugar, beating untl creamy. Add eggs, one at a time, beating well after each addition. Add chocolate mixture, cherry liqueur, and vanilla, mix until blended. Pour into prepared crust. Bake at 160ºC . for 60 minutes. Turn oven off. Let stand in oven with door ajar 1 hour. Remove, cool completely. Chill 24 hours. Spread cherry pie filling over top of cheesecake leaving 3 cm from the edge. Decorate edge with whipped cream, if desired.