Reduce oven temperature to 250°F
Beat room temperature cream cheese and sugar until smooth
Add eggs one at a time, mixing well between each
Mix in vanilla, salt and sour cream until smooth
Pour into prepared pans with pre-baked crust
Place in water bath (hot water halfway up sides)
Bake until mostly set with small jiggly center (1 hour 30 minutes for two 6" pans or up to 2 hours for one 9" pan)
Remove from water bath and cool to room temperature
Cover with plastic wrap and refrigerate overnight
Run a knife around edges to loosen, then submerge bottom in hot water before flipping out