Preheat oven to 325 degrees.
Set water to boil.
Using an electric mixer, beat cream cheese on medium until fluffy, scraping down side of bowl.
Gradually add sugar, beating until fluffy.
Beat in vanilla extract and salt.
Beat in eggs, one at a time, scraping down side of bowl after each addition.
Beat in sour cream.
Line the bottom of mini spring form pan with tin foil.
Pour in filling; place in a roasting pan.
Pour in boiling water to come halfway up side of spring form.
Bake until just set in center, about 25 minutes.
Remove pan from water; let cool 20 minutes.
Run a paring knife around edge and lift out; let cool completely.
Put in fridge once cooled completely.