1. Preheat oven to 325 degrees.
2. In a small bowl combine graham crackers, 1/4 cup sugar and butter. Press mixture evenly onto the bottom and halfway up the sides of a 9-inch springform pan.
3. In the workbowl of a food processor, combine 2 1/2 cups blueberries and 1 tbs cornstarch. Process until smooth.
4. Pour mixture into a small saucepan and cook over medium heat for 15 minutes or until slightly thickened, stirring constantly. Set aside to cool, reserving 1/2 cup mixture for glaze.
5. Beat cream cheese with mixer until fluffy.
6. Gradually beat in 1 cup sugar.
7. Add eggs, one at a time, beating well after each addition. Stir in remaining 2 tbs cornstarch and salt.
8. Pour batter into crust. Spoon cooled blueberry mixture over batter and GENTLY swirl with a knife.
9. Bake for 1 hour or until set. Remove from oven and cool on a wire rack for 20 minutes.
10. In a small bowl combine sour cream, 2 tbs sugar, vanilla. Stir until blended, and spread over cooled cheesecake.
11. Return to oven, bake for 10 minutes.
12. Remove from oven. Gently run a knife around edges to release sides. Cool completely in pan on a wire rack.
13. Cover and chill for 8 hours or overnight.
14. In a saucepan combine reserved blueberry mixture, 1/2 cup water and 1/4 cup sugar.
15. Cook over medium heat until thickened, stirring constantly.
16. Stir in remaining 1 cup blueberries. Set aside to cool.
17. Remove sides of springform pan to serve.
18. Spoon blueberry sauce over cake.