1 9" deep dish pie shell

7 c apples (6-7)—peeled and sliced thin
1/2 c sugar
1 tbsp lemon juice
1/2 tsp ground cinnamon
1/2 tsp ground allspice
1/4 tsp ground nutmeg
1 pinch cayenne pepper
2/3 c all purpose flour
2 tbsp butter

Streusel Topping
1 c packed brown sugar
1 c quick cooking oatmeal
3/4 c all-purpose flour
1/4 tsp salt
1 tbsp fresh lemon zest
1 stick chilled unsalted butter, cut into little chunks

Heat oven to 425F. Mix all filling ingredients, except butter, together in a large bowl and toss to coat until no dry ingredients are left in bottom of bowl.
Add all topping ingredients to a food processor and pulse several times until mixture just begins to clump into pea-size lumps.
Pour filling into pie shell and dot with butter. Bake for ten minutes in center of oven. Sprinkle topping over pie, reduce heat to 350F, and continue baking for 35 minutes.