Gluten, Sugar & Dairy Free Apple Pie with an Oatmeal Cookie Crust

This is my gluten, dairy & sugar free version of apple pie. I saw a similar recipe on the Spicy Bohemian blog. I made it sugar free and made some other adjustments as well. 

Crust:

1 1/2 cups gluten-free rolled oats
1/2 c almond flour
1/4 c oat flour
1/4 teaspoon salt
3/4 teaspoon cinnamon
3 tablespoons brown sugar substitute
1/2 teaspoon vanilla extract
1/2 cup unsalted butter, melted

Combine all the dry ingredients in a bowl and mix well. In a separate bowl, mix the vanilla in with the melted butter. Add the liquid ingredients to the dry and mix well. Press firmly into the bottom and sides of a 9-inch pie pan, keeping a handful of crust for the topping. 

Filling:
3 medium-sized granny smith apples, thinly sliced
3 T fresh lemon juice
1 t cinnamon
1/4 t allspice
1/4 t nutmeg
1 1/2 T cornstarch or tapioca starch
1/4  c maple syrup

Preheat oven to 375°F.

Put the sliced apples in a large bowl, drizzle with lemon juice and mix well. Add the spices, lemon rind, and cornstarch and mix well again. Gently stir in the sugar until well combined.

Layer the filling into the unbaked crust and sprinkle with the handful of reserved crust. 

Wrap foil around edges of pie and bake for 30 minutes.
Remove foil and bake 20 more minutes.

Serve warm.