In the meantime, prepare the filling: whisk all filling ingredients together until light and smooth. Pour over base.
Cook for 45 minutes (the top should still be jiggly but have an overall appearance of being set).
Turn off the oven and leave the cheesecake inside until it has cooled (it will still be a little warm to the touch but you should be able to remove it from the oven without a cloth/oven-mitten. If you miss this step and remove the cheesecake immediately, it is more likely it will develop huge cracks due to the sharp switch in temperature.
Leave to cool completely, cover and then place in the fridge overnight.