Citrus Liqueur Cheesecake

Preheat oven to 475°F (245°C). Butter bottom and sides of a 10-inch springform pan. Melt butter in a small saucepan. Add cookie crumbs and mix until thoroughly combined. Press mixture onto bottom and 1-inch up sides of prepared pan. Refrigerate until needed. In a large bowl, combine cream cheese, sugar, flour and orange peel. Beat with an electric mixer on medium speed until smooth. Add eggs and yolks, one at a time, beating well after each addition. Stir in cream and liqueur until well combined. Pour mixture into crust and bake for 10 minutes. Reduce heat to 200°F and bake 1 1/2 hours or until set. Turn off oven and leave cheesecake in oven with the door ajar, for 30 minutes. Finish cooling cheesecake on a wire rack. Cover and refrigerate until completely chilled (6 to 8 hours). To serve, run a sharp knife around the edge to loosen. Remove pan and cut into wedges.