This very sweet take on apple pie combines apples, warm spices, caramel and toffee into a hybrid pie with both a crumbly, crisp, streusel and a lattice pastry top.
Combine the flour, oats, brown sugar, caramel/toasted sugar, cinnamon and salt in a food processor. Pulse until everything is well combined, the oats should still be somewhat coarse, not processed into oat flour.
1/2 cup flour, 1/2 cup oats, 1/4 cup brown sugar, 1/4 cup caramel/toasted sugar, 1 tsp ground cinnamon, 1/4 tsp salt
Add the butter and pulse until the mixture forms a coarse crumbly texture.
4 tbsp butter
Stir in the crushed toffee until evenly distributed. Set aside (this can be made a couple days ahead and stored in the refrigerator)
6 oz toffee
Make the Egg Wash
In a small bowl, beat the egg and milk together until homogenous; set aside.
1 egg, 1 tbsp milk
Assemble the Pie
Roll out both pie crusts to about 1/8" thickness and about 13"-15" diameter. Reserve one crust in the refrigerator. Fit the second pie crust into a 9 1/2" or 10" deep dish pie plate. Be careful not to stretch the crust, ease it down into the corners of the pie plate without forcing it.
2 9"-10" pie crusts
Sprinkle about 1/3 of the cinnamon toffee streusel in the bottom of the prepared pie shell.
Spoon the apple filling over the toffee streusel (ideally the apple pie filling should be cool room temperature at this point). Distribute the remaining streusel evenly over the top of the filling.
3-4 quarts caramel apple pie filling
Remove the reserved crust from the refrigerator. Using a pastry cutter, pizza wheel or sharp knife, cut it into even, narrow strips. Weave a very loose lattice over the top of the pie, leaving about 2" between the pastry strips, you want to leave a good amount of the streusel exposed to get nicely crisped during baking. Trim the ends of the pastry strips even with the edge of the pie. Fold the overhang from the bottom crust over the edges of the lattice and create a pinched/crimped decorative edge. If the pastry crust is starting to get soft at this point, place the entire pie in the refrigerator for about 20 minutes or so, allowing the butter in the dough to firm up again. (For assistance with weaving a lattice crust, check out "How to Make a Stunning Lattice-Top Pie, According to a Pastry Chef" by Stella Parks)
Preheat the oven to 450°F. While the oven is preheating, carefully brush the lattice work pastry with the egg wash, avoid getting the egg wash on the exposed streusel.
Bake for 15 minutes; lower the oven temperature to 350°F and continue baking for about 45 minutes. If the crust is browning too quickly cover the edges lightly with foil or a pie crust shield.
Allow pie to cool before serving. Serve room temperature or warm. Drizzle slices with caramel sauce if desired. Store leftovers in the refrigerator.