Preheat oven to 300°F. Tightly wrap 3 layers of aluminum foil around the outside and bottom of a springform pan. Coat the entire inside of the pan with butter; set aside.
In a stand mixer (using a paddle attachment), beat the cream cheese and butter on medium-high until smooth.
Add eggs (one at a time) until completely blended, smooth and glossy.
Add sour cream and beat until smooth.
Add cornstarch, vanilla extract and lemon juice; beat until smooth (about 5 minutes).
Pour mixture into the springform pan; then place the springform pan into a large round roasting pan (allow there to be at least 2-3 inches in between the pans on all sides).
Place into the oven; pour boiling water into the roasting pan, taking care not to let the water go above the top of the aluminum foil; close the oven.
Bake for 2 hours until lightly browned on top.
After 2 hours, remove from oven. Take the springform pan out of the roasting pan and remove the aluminum foil. Place the springform pan on a cooling rack and allow the cheesecake to cool to room temperature, untouched.
Cover and refrigerate overnight.