Preheat oven to 325. Coat bottom & sides of 10 inch springform pan with nonstick cooking spray. Sprinkle bottom with crumbs & set aside. Put cottage cheese & cream cheese in food processor. Process until smooth. Add 1 cup sugar, whole eggs, egg whites & vanilla. Process just until smooth. Pour 3 cups batter into a separate bowl. Add cocoa & 1/4 cup sugar to mixture in processor. Process until well mixed. Spoon alternating mounds of cocoa mixture & plain mixture into springform pan. Swirl with a knife to make a marbled pattern. Bake 1 hour or until almost set. Turn oven off. Remove cheesecake from oven. Run a sharp knife around edge of pan. Return cake to oven. Let stand 1 hour with door ajar. Cover & chill 8 hours. Remove sides of pan. Place on serving platter. Sauce: in saucepan, mix together cornstarch & water. Stir until well mixed. Add corn syrup, cocoa & sugar. Turn heat to medium & stir until thickened & bubbly. Stir in vanilla & let cool. To serve, spoon some sauce into bottom of dessert plates. Place a slice of cheesecake on top. THE DESSERT SHOW ----