Instructions

1. For the Crust:
2. Preheat oven to 350F.
3. In bowl of a food processor, combine oats, flour, brown sugar and salt, and pulse until oats are coarsely chopped.
4. Add butter and pulse until evenly moistened.
5. Transfer mixture into a 9-inch pie pan.
6. Press crumbs evenly into bottom and up sides of the pan.
7. Set pan on a rimmed baking sheet and bake for 12 minutes it's going to bake more when you bake the full pie.
8. Set aside to cool while you work on filling.
9. For the Filling:
10. Freeze your oatmeal pies for about 2 hours. Then scrape out the filling of the pies. Freezing helps, but you will still get pieces of oatmeal cookie pie in there. It's fine. Save 3/4 of a cup oc the oatmeal cookie pie pieces for the topping.
11. In a large bowl, whisk sour cream, oatmeal pie filling, sugar, egg, flour, salt, and until even mixed.
12. Add the apples; mix until combined, then let stand on the counter for 30-45 minutes.
13. Preheat the oven to 400 degrees F.
14. Layer the apples and juices into the pie pan, rather than pouring and mounding in the center. For overall look and an even bake, we want to avoid vacant and areas of void as the apples further soften under heat.
15. Spatula remaining sour cream filling into the pie and give the apples one final gentle but firm press.
16. Bake on center rack for 15 minutes.
17. After 15 minutes, reduce the temperature from 400° to 350°F and bake for another 30 minutes.
18. Meanwhile, make the crumb topping.
19. For the Crumb Topping:
20. Combine the flour, sugar, oatmeal pie crumb pieces, and salt. in a medium bowl.
21. Drizzle the melted butter and stir with a fork, then spatula or your hands until the mixture is a mix of small to medium crumbs. Refrigerate until ready for use.
22. After the 30 minutes at 350F is up, remove the pie from the oven and crumb topping from the refrigerator.
23. Remember which side of the pie was facing front, as we are going to place that towards the back when returning to the oven. While adding the streusel, use your hands to break then squeeze the crumbs into varying sizes while adding to the pie.
24. Once finished adding, give another gentle press.
25. Place a pie shield or foil around edges to prevent over browning, slide a pan one rack below, and rotate the pie 180°.
26. Continue baking for another 20 minutes, or until the top is toasty golden and a butter knife slides with ease through the inside apples. 
27. Once pie finishes baking, transfer to a wire rack. Let cool for at least three hours or overnight.
28. Slice and be one with the beauty you created.
29. Serve with LIttle Debbie Oatmeal Creme Pie Ice Cream or vanillla ice cream.