Place a greased 9-in springform pan on a double thickness of heavy-duty foil. Securely wrap foil around pan; set aside.
In a small bowl, combine cookie crumbs and pecans; stir in butter. Press onto the bottom and 1 inch up the sides of prepared pan. Bake for 9 to 11 minutes. Cool on wire rack.
In large mixing bowl, beat cream cheese and 1/2 cup sugar until smooth. Beat in vanilla. Add eggs; beat on low speed just until combined.
Place 1 cup filling in a small bowl; stir in the pumpkin, cinnamon, nutmeg and remaining sugar. Remove 3/4 cup pumpkin filling and set aside. Pour remaining pumpkin filling into the crust; top with plain filling. Drop reserved pumpkin filling by spoonfuls over top; cut through filling with a knife to swirl.
Place pan in a large baking pan; add 1 inch of hot water to larger pan. Bake for 50-60 minutes or until center is just set and top appears dull.
Remove springform pan from water bath. Cool on 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. Garnish with whipped topping, if desired.