To Make Crust: In a medium bowl, combine digestive biscuit crumbs, 2 tablespoons white sugar and chopped pecans. Mix well then stir in melted butter or margarine. Mix until ingredients are thoroughly combined. Press mixture into pan. Bake in preheated oven for 8 to 10 minutes, until lightly browned. Cool to room temperature.
To Make Cream Cheese Filling: In medium mixing bowl whip cream cheese until fluffy. Mix in icing sugar. Scrape sides of bowl. Add vanilla essence. Add orange liqueur if desired. Mix well.
In a separate bowl, beat cream until soft peaks form. Fold into cream cheese mixture. Spoon filling into cooled crust. Cover with plastic wrap or aluminium foil and chill at least 3 hours.
To Make Cranberry Topping: In a medium saucepan, combine cranberries, 1 cup white sugar and 1 tablespoon water. Cook over medium heat, stirring constantly, until mixture comes to a full boil and cranberries begin to burst. Remove from heat.
Mix cornflour and 2 tablespoons water together in a small bowl until smooth then stir into cranberry mixture. Return pan to heat. Cook until mixture boils and thickens, stirring constantly. Remove from heat and cool to room temperature.
Spread cranberry topping over cream cheese filling. Chill pie thoroughly before serving.