In a large saucepan, combine sugar and cornstarch. Stir in cranberry juice until smooth. Add cranberries. Bring to a boil over medium heat; cook and stir for 2 minutes or until thickened. Remove from the heat; set aside.
In a small bowl, combine cracker crumbs and sugar; stir in butter. Press onto the bottom of a greased 9-in. springform pan. Place pan on a baking sheet. Bake at 325° for 10 minutes. Cool on a wire rack.
In a large bowl, beat cream cheese and sugar until smooth. Add flour and beat well. Add eggs, beat on low just until combined. Add eggnog and vanilla; beat just until blended. Pour two-thirds of the filling over crust. Top with half of the cranberry mixture (cover and refrigerate remaining cranberry mixture). Carefully spoon remaining filling on top. Return pan to baking sheet.
Bake at 325° for 60-70 minutes or until center is almost set. Cool on a wire rack for 10 minutes. Carefully run a knife around edge of pan to loosen; cool 1 hour longer.
Refrigerate overnight. Remove sides of pan. Spoon remaining cranberry mixture over cheesecake. Refrigerate leftovers.
Yield: 12 servings.