In a large bowl, combine cookie crumbs and butter. Press mixture firmly on the bottom and up sides to rim of a buttered 9-inch pie plate. Chill.
Meanwhile, in large mixer bowl, beat cream cheese until fluffy. Gradually beat in sweetened condensed milk until smooth. Stir in lemon juice and liqueurs. Fold in whipped topping. Chill 20 minutes. Pour chilled filling into crust. Chill or freeze 4 hours or until set.
Garnish with a dollop whipped cream and a whole Oreo cookies or chocolate curls. Refrigerate or freeze leftovers.
Cook's Note: A prepared spring-form pan or tart pan with removable bottom may also be used.