In a saucepan, combine the first four ingredients; bring to a boil. Reduce heat; cook and stir over medium heat for 2 minutes. 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-inch springform pan. Bake at 325 degrees for 10 minutes. Cool on a wire rack.
In a mixing 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 chill remaining cranberry mixture). Carefully spoon remaining filling on top. Bake at 325 degrees 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.
*Editor's note: This recipe was tested with commercially prepared eggnog.