01 - Preheat oven to 320°F. Grease and line a 9-inch springform pan.
02 - Crush biscuits into fine crumbs and blend with melted butter until uniform. Press firmly into the pan bottom and chill while preparing filling.
03 - Beat cream cheese with sugar until smooth and creamy. Incorporate eggs one at a time, mixing thoroughly after each addition.
04 - Blend in cornstarch, then add heavy cream, Irish cream syrup, and vanilla. Beat until silky and fully combined.
05 - Pour filling over chilled crust. Tap gently to release air bubbles. Bake 55–65 minutes until edges set and center retains slight jiggle.
06 - Turn off oven, crack door open, and cool cheesecake inside for 1 hour.
07 - Refrigerate at least 4 hours, preferably overnight, before serving.
08 - Whip heavy cream with powdered sugar to soft peaks. Spread or pipe over chilled cheesecake. Garnish with grated chocolate or cocoa powder.
09 - Slice and serve chilled.