For Crust: Combine graham cracker crumbs and granulated sugar in medium bowl; stir in butter. Press onto bottom and 1 inch up side of 9-inch springform pan. Bake in preheated 350 F oven for 6 to 8 minutes (do not allow to brown). Cool on wire rack.
For Cheesecake: Beat cream cheese, granulated sugar and brown sugar in large mixer bowl until fluffy. Beat in eggs, pumpkin and evaporated milk. Add cornstarch, cinnamon and nutmeg; beat well. Pour into crust.
Bake in 350 F oven for 55 to 60 minutes or until edge is set but center still moves slightly.
For Topping: Combine sour cream, granulated sugar and vanilla in small bowl. Spread over surface of warm cheesecake. Bake in 350 F oven for 5 minutes. Cool on wire rack. Chill for several hours or overnight. Garnish with orange segments. Remove side of springform pan before slicing.
Please note that some ingredients and brands may not be available in every store.