CRUST: Combine crust ingredients. Mix well; press onto bottom of 25 cm springform pan. Bake in preheated 200ºC for 10-15 minutes. Reduce oven temperature to 180ºC
1ST LAYER: Crumble cheese in large bowl. Add 1 tsp vanilla, 1 cup sugar and eggs; beat at high speed with electric mixer until blended and smooth, about 4 minutes. Pour over crust. Bake at 180ºC for 40 minutes until set (not completely firm). Remove from oven; cool 10 minutes.
2ND LAYER: Combine sour cream, sugar and half ts vanilla. Spread over top of cheesecake. Bake at 180ºC for 5 minutes. Cool; spread blueberry topping over top. Refrigerate before serving.
TOPPING: Mix cornstarch with cold water to form smooth paste. Stir in blueberries; cook until thickened. Let cool; spread on cheesecake. Cool 1 hour then refrigerate.