1Preheat oven to 325. Put a kettle of water on to heat for the water bath. Coat a 9 in springform pan with cooking spray. Wrap the outside bottom of the pan with a double thickness of foil.
2To prepare crust---combine crumbs and oil in a bowl. Press into the bottom of the pan. Bake 7 minutes.
3To prepare filling and bake cheesecake--puree cottage cheese in a food processor or blender until very smooth. Pour into a large bowl, add cream cheese, sugar and 3 tablespoons corn starch; mix with an electric mixer until smooth. Add egg, egg whites, sour cream, vanilla and salt; blend well. Measure 3 1/2 cups of the batter into a separate bowl, stir in lemon juice. To the remaining filling, add pumpkin, brown sugar, molasses, spices and the remaining 1 tablespoon of cornstarch, blend well. Pour 1 cup of the vanilla mixture into the center of the crust. Then pour about 1 cup of the pumpkin filling into the center of the vanilla filling. Alternate the remaining fillings in the same manner, concentric circles will form as they spread. To create a marbled effect, gently swirl a knife or skewer through the fillings.
4Place the cheesecake in a roasting pan and pour in enough boiling water to come about 1/2 inch up the side of the springform pan.
5Bake the cheesecake about 50 minutes, until the edges are set, but the center still jiggles. Turn off the oven, slide a knife coated in non-stick spray around the edges of the pan. Let it stand in the oven, with the door ajar, for about an hour. Transfer from the bath to a wire rack, remove foil. Let cool to room temperature for about 2 hours. Refrigerate until chilled.