In a bowl, combine crumbs and sugar; stir in butter. Press onto the bottom and 1-1/2 in. up the sides of a greased 9-in. springform pan. Bake at 350° for 5-7 minutes or until set. Cool for 10 minutes.
In a mixing bowl, beat cream cheese and brown sugar until smooth. add the pumpkin, cornstarch, cinnamon and nutmeg; mix well. Gradually beat in milk and eggs just until blended. Pour into crust.
Place pan on a baking sheet. Bake at 350° for 55-60 minutes or until center is almost set. Combine the sour cream, sugar and vanilla; spread over filling. Bake 5 minutes longer. Cool on a wire rack for 10 minutes. Carefully run a knife around edge of pan to loosen; cool 1 hour longer. Chill overnight.
Remove sides of pan; let stand at room temperature 30 minutes before slicing. Sprinkle with cinnamon. Refrigerate leftovers. Yield: 12-14 servings.