In a large mixing bowl, beat cream cheese, sour cream, cornstarch,
vanilla, salt, and remaining sugar until smooth. Add eggs, beat
until just combined. Top with half the rhubarb sauce; cut
through the batter with a knife to gently swirl
rhubarb. Layer with remaining filling and
rhubarb sauce; cut through top laters with a
knife to gently swirl rhubarb.