Preheat oven to 300 degres F. Press crust mixture into the bottom and partially up the sides of a 9" spring-form cake pan. Beat cream cheese until smooth. Gradually beat in sugar. Beat in vanilla and lemon zest. Beat in eggs one at a time, scraping the sides of the bowl after each addition. Pour half the batter into the cake pan, and then sprinkle half the cherries over top. Pour in remaining batter. Bake 50-60 minutes, or until the centre barely jiggles when the pan is gently tapped. Cool to room temperature. Refrigerate several hours before unmoulding.
Make the sauce by placing chocolate and milk in a heatproof bowl. Set over simmering water. Cook until the chocolate has melted and is blended into the milk. Stir in orange liqueur. Remove from heat and cool to room temperature. Store chocolate sauce in the fridge until needed. (Heat for a few seconds in the microwave to make it fluid again before using.)
Decorate top or individual slices of cake with remaining cherries. Serve slices on a pool chocolate sauce. Garnish with mint and few whole cherries.
Note: To prevent cheesecake from cracking as it bakes, place a shallow pan of water on the bottom rack of the oven before baking.