1. Preheat oven to 325°.
2. To prepare crust, combine first 3 ingredients in a medium bowl. Drizzle with butter; toss with a fork until moist. Firmly press mixture into bottom of a 9-inch springform pan coated with cooking spray. Bake at 325° for 10 minutes; cool on a wire rack.
3. To prepare filling, combine 2 1/2 cups blueberries and 1 tablespoon cornstarch in a food processor, and process until smooth. Place puree in a small saucepan; bring to a boil. Cook 6 minutes or until slightly thick, stirring constantly. Cool slightly. Reserve 1/2 cup blueberry puree for sauce; set remaining 1 cup blueberry puree aside.
4. Place cheeses in a large bowl; beat with a mixer at high speed for 3 minutes or until smooth. Combine 1 cup sugar, 2 tablespoons cornstarch, and salt. Add sugar mixture to cheese mixture; beat well. Add eggs, 1 at a time, beating well after each addition. Pour batter over prepared crust. Pour 1 cup blueberry puree over batter; gently swirl with a knife. Bake at 325° for 1 hour and 10 minutes or until cheesecake center barely moves when pan is touched. Remove cheesecake from oven (do not turn oven off); place cheesecake on a wire rack.
5. To prepare topping, combine sour cream, 2 tablespoons sugar, and vanilla in a small bowl, stirring well. Spread sour cream mixture evenly over cheesecake. Bake at 325° for 10 minutes. Remove cheesecake from oven; run a knife around outside edge. Cool to room temperature. Cover and chill at least 8 hours. Remove sides of springform pan.
6. To prepare sauce, combine reserved 1/2 cup blueberry puree, 1/4 cup sugar, and water in a small saucepan. Cook over medium heat for 8 minutes or until sauce is thick, stirring constantly. Gently fold in 1 cup blueberries. Remove from heat, and cool. Serve sauce with cheesecake.