Preheat oven to 180 degrees C. Spray a 20cm springform pan with the oil.
Place the biscuits in a food processor and process until finely crushed. Add the butter and process until well combined. Use the back of a spoon to press the biscuit mixture over the inside of the greased pan to evenly cover the base and come 2/3 of the way up the sides. Place in the fridge while making the filling.
To make the filling, use electric beaters to beat the cream cheese, caster sugar and vanilla essence in a medium bowl until the mixture is light and creamy. Add the lemon rind, lemon juice, egg yolks and cream. Beat until well combined and the mixture is light and fluffy.
Use clean electric beaters or a hand whisk to whisk the egg whites in a medium mixing bowl until stiff peaks form. Add to the cream cheese mixture and use a large metal spoon to fold until just combined.
Pour mixture into prepared pan. Bake in preheated oven for 40 minutes or until golden and just set in the centre. Remove from the oven and allow to cool completely.
Cover loosely with plastic wrap and place in the fridge overnight to firm (not to be eaten that day as is too light and fluffy). Remove from the fridge 10 minutes before serving.