Sweet potato cheesecake

Crust:
  1 1/2 c  Graham cracker crumbs
    1/4 c  Granulated sugar
    1/3 c  butter or margarine; melted
           Cheesecake:
      3    3 oz pkgs cream cheese; soft
      1 c  Granulated sugar
    1/4 c  Light brown sugar
  1 3/4 c  Sweet potatoes, mashed
      2    Eggs
    2/3 c  Evaporated milk; undiluted
      2 tb Cornstarch
    1/4 ts Ground cinnamon
    1/8 ts Ground nutmeg
           Topping:
      2 c  Sour cream; room temperature
    1/3 c  Granulated sugar
      1 ts vanilla extract
 
  Recipe by: Sweet Potato Festival, Vardamon, Mississippi, 1994
  Crust:  Combine crumbs, sugar, and butter in bowl.  Press onto bottom and 1
  inch up on sides of 9 inch springform pan.  Bake at 350 degrees for 6 to 8
  minutes.  Do not allow to brown.  Remove from oven and cool.
  
  Cheesecake:  Beat cream cheese, sugar and brown sugar in large bowl.  Beat
  sweet potatoes, eggs, and milk.  Add cornstarch, cinnamon and nutmeg.  Beat
  well.  Pour into crust.  Bake at 350 degrees for 55 to 60 minutes or until
  edge is set.
  
  Topping:  Combine sour cream, sugar and vanilla.  Spread over warm cheeseca
  
   Return to 350 degree oven and bake 5 minutes.  Cool on wire rack.  Remove
  side of pan and chill several hours or overnight.