Tightly wrap 2 layers of aluminum foil around the outside of a 10 inch springform pan covering bottom and sides.
Preheat oven to 300º.
Beat cream cheese and butter until smooth.
Add one egg at a time until smooth.
Add sour cream.
Add sugar, cornstarch and vanilla,
Beat until smooth, about 2 minutes.
Pour into springform pan and place in oven.
Fiill a roasting pan or cheesecake moat with boiling water and place on the rack below the cheesecake.
Bake for approx 90 mins. (original says up to 2 hours, but mine was done at 90 mins.)
It should be lightly browned on top and still have a little jiggle to it.
My time was based on a convection oven so a regular oven may need the full 2 hours.
Let cheesecake cool to room temp and chill in fridge overnight.