Homemade or store-bought crust will work for this recipe. I typically buy a prepared crust simply to save time.
1. Preheat oven to 400 degrees.
2. Roll out pie dough and line 9-inch pie plate. Freeze for at 15-20 minutes to firm dough.
3. Prepare crumb topping by combining sugars, cinnamon, flour and salt. Cut in butter using a pastry cutter or two knives until mixture resembles large peas. With hands, press topping together to form large clumps. Refrigerate until ready to use.
4a. Peel, core, and slice apples into 1/4-inch wedges.
4b. 4. In a large bowl, whisk together sugar, cornstarch, cinnamon and salt. Add apples and toss to evenly combine.
5. Add sour cream and vanilla to apple mixture and toss well to coat evenly.
6. Spoon apple mixture into chilled crust.
7. Sprinkle top of apple mixture with crumb topping.
8. Place pie on foil-lined baking sheet to catch and overflow during baking. Bake pie for 1 hour. Then, turn oven down to 350 degrees and bake for another 35-45 minutes or until the filling in the center is bubbling.
If needed, you can loosely cover pie with aluminum foil towards the end of cooking to prevent over browning.