Preheat oven to 180 degrees C. In a medium bowl combine crumbs, butter and icing sugar. Mix well and press into the bottom of a 23cm springform pan. Bake in preheated oven for 10 minutes. Remove from oven and allow to cool. Turn off oven.
Dissolve lemon jelly crystals in boiling water. Let cool until thick but not set. In a large bowl beat cream cheese, white sugar and vanilla until smooth. Set aside.
In a separate bowl whisk evaporated milk until thick and stiff peaks form. Pour in lemon jelly and keep mixing until well blended. Fold in cream cheese mixture.
Pour filling into crust. Chill in refrigerator for at least 3 hours before serving.