This is an Apple Pie that's been taken up several notches with a layer of moist cream cake, and then sent over the top with a layer of cinnamon streusel.
Place pie crust in 9 inch pie pan (mine was a 9.5" pan, so that will work too). Spoon the apple pie filling into the pie crust and smooth into an even layer. Set aside.
In a medium bowl whisk together the sugar, flour, sour cream, eggs and vanilla until smooth. Pour over the apples.
Prepare the topping by adding the topping ingredients to a bowl and use a fork or pastry cutter to combine into a coarse crumble mixture. Place in the freezer until ready to use.
Bake pie for 55 minutes, remove from oven and increase temperature to 400 degrees.
Top the pie with all of the streusel mixture. Return pie to oven and continue baking for 10 minutes.