Prepare cake pan by greasing the inside with baking spray and/or parchment paper. Then set the pan on tin foil and wrap the edges of the foil around the pan. (I did this about 3 times to prevent leakage once the pan goes in the water bath). Set pan in roaster, fill roaster with water so it comes about halfway up the cake pan. Set aside.
In double boiler, melt cream cheese, butter and milk. Cool the mixture to lukewarm.
In one bowl, pour the cheese mixture in and then mix in flour, corn starch, egg YOLKS, and lemon juice. Mix to a smooth consistency, set aside.
Whisk egg whites and cream of tartar until foamy. Slowly add sugar while mixing until soft peaks form. Turn on oven to 325°F (Don't stop at the gooey white stage; keep going! Think a slightly melty soft-serve ice-cream cone. If you are going to do this by hand it will take at least 30 minutes. Trust me on this one!).
Add the egg white mixture to the cheese mixture and mix well with a spoon.
Once oven has reached temperature, put the roaster with pan inside.
Bake for 50 minutes at 325, then for 20 minutes at 320.
Check for done-ness by inserting toothpick into center of cake. (don't use a knife, it will cause cake to deflate). If it needs to bake more, check every 5 minutes.
Remove immediately when done and let cool to room temperature.
Serve as-is or top with preserves or whipped cream (or both!).
If the cake is plain, you can store it covered at room temperature If you put preserves or whipped cream, place in airtight container in the refrigerator.
The cake might crack at the top or deflate a bit in the center. To avoid this, don't over-beat the eggs or mixture (introduces air into the batter, causing cake to sink).
Caster sugar or Baker's sugar is superfine sugar. It's sold in a giant milk-carton looking thing. It isn't powdered sugar (aka confectioner's sugar). If you can't find it, you can put the same amount in a blender and mix well.
Separate the eggs while they are cold, then, place the yolks back in the fridge and leave the whites out. They whip better at room temperature.
Philadelphia seems to work best. Don't sub for reduced-fat or fat-free. I'm thinking you could probably try strawberry too, hmm --
Cake flour, like baker's sugar, is superfine. It's sifted to a more powder-like consistency and helps the cake be more fluffy. You can find it at Super Target, I found it at Albertson's as well. It works a lot better with cake flour than regular flour.
