When I first started making it, I used a couple layers of regular foil, but it wasn't wide enough to go up the sides of the springform pan. Water kept leaking inside and make the cake soggy on the bottom. I put the whole pan in a roasting pan and then fill it up with water an inch or more.

Whatever works! Glad you like it. I used to make a pumpkin version that was really good. I think the recipe for that is somewhere in the first couple of pages of this thread.