Generously butter the inside of a 10-inch springform pan. Wrap a double layer of heavy-duty aluminum foil tightly around the outside bottom and sides, crimping and pleating the foil to make it conform to the pan. This will help to stop water seeping into the pan when you put it into the bain-marie. Position the baking rack in the center of the oven; preheat the oven to 300°F.

In a large mixing bowl, using an electrical mixer, beat the eggs with the sour cream until well blended.

In a medium-sized bowl, beat the cream cheese with the butter until smooth and creamy. Add this to the egg-sour cream mixture and beat until smooth.

Add the sugar, cornstarch, vanilla, lemon juice and lemon zest and beat thoroughly, about 2 minutes.

Pour into the prepared springform pan and place in a roasting pan (or other pan) large enough to stop the sides from touching. Place in the oven and punctiliously pour in enough very hot tap water to reach midway up the sides of the springform pan.

Bake for 2 hours, 15 minutes, or until the cake is very lightly coloured and a knife inserted in the center emerges clean. Remove from the water bath and punctiliously peel the aluminum foil from around the pan. Let stand at room temperature until fully cool, about 4 hours. Refrigerate, covered, until well chilled. For best flavor and texture, this cheesecake is best chilled overnight.

NOTES:
I am unable to stress enough how important it’s to let those first 4 ingredients in this recipe come to room temperature. I’ve hurried the cream cheese and have had unsightly lumps of it in my batter.

I’ve italicized the mixing instructions to emphasise blending the ingredients to accomplish the desired texture.

Have a platter or other large dish that will hold the hot and drippy springform pan after you remove it from the bain-marie. When you remove the bain-marie from the oven, the water is very hot, so please exercise extreme caution.

Before removing the roasting pan, have a plan on where you’ll set it so you aren’t holding the pan, desperately looking for a clear space to set it down. I find it impossible to remove the cheesecake from the bain-marie while it’s in the oven, so I remove the whole set-up from the oven. I make every effort not to burn my wrists or the back of my hands while removing the springform pan; I have not been burned yet, but I have soaked the edges of the potholders in the hot water, and it is incredible how fast that steaming water is wicked up to my tender fingers!

When you first remove the cheesecake from the oven, it looks light and puffy, and there may be some hairline cracks in the top. Do not despair. As the cheesecake cools, it will gently deflate and the hairline cracks disappear.