In a large bowl, toss apples with lemon juice and vanilla. Combine the pecans, sugars, cinnamon and cornstarch: add to apple mixture and toss to coat.
Pour caramel topping over bottom of pastry shell.
Top with apple mixture (shell will be full.) Drizzle with butter.
In a small bowl, combine the flour, pecans and sugar. Cut in butter until mixture resembles coarse crumbs. Sprinkle over filling.
Bake at 350 degrees for 55-65 minutes or until filling is bubbling and topping browned. Immediately drizzle with caramel topping.
Samantha & Amy Gill, Monclova, Ohio