In a medium bowl, combine piecrust ingredients. Press into the bottom and to the top of the sides of the springform pan. Place pan on a baking tray and bake 10 minutes. Let cool. Lower heat to 325º.
In a medium saucepan over medium heat, combine berry topping ingredients, stirring occasionally. Cook 8 to 10 minutes. Cool to room temperature; then cover and chill.
In a standing mixer, beat cream cheese until fluffy. Add sugar slowly, scraping the sides of the bowl often. Beat in cornstarch and vanilla. Add eggs 1 at a time, scraping well after each addition. Scrape filling mixture into cooled shell (it will fill shell only halfway) and bake 30 minutes.
Stir sour cream, sugar, and vanilla together to blend. After cheesecake has baked 30 minutes, remove carefully and gently layer dollops of sour cream mixture over filling. Spread for an even layer, and return to the oven for 30 minutes longer. Remove, and cool cheesecake to room temperature. Chill overnight before garnishing.
To garnish, spread berry topping over chilled cheesecake and chill again until ready to slice.