Apple Pie with Oatmeal Streusel

Preheat the oven to a high temperature, 425 degrees F (220 degrees C), to ensure it reaches the optimal heat for baking.

Make the apple pie filling by combining sliced apples in a large bowl. In another bowl, blend together white sugar, flour, cinnamon, nutmeg, and allspice until they form a cohesive mixture; then sprinkle this blend over the apples and mix until they are evenly coated.

Extract the pie shell from its frozen state; pour the apple mixture into the pie shell and add small pieces of butter on top. Cover the filling with a thin layer of aluminum foil, but do not seal it.

Bake the pie in the preheated oven for 10 minutes to allow the filling to start cooking.

Simultaneously, prepare the streusel topping by blending together flour, oats, brown sugar, lemon zest, and cinnamon in a medium bowl until they form a uniform mixture. Use your fingers or a pastry blender to cut the butter into the mixture until it becomes crumbly.

Remove the pie from the oven and sprinkle the streusel topping evenly over its surface.

Downsize the heat to a moderate temperature, 375 degrees F (190 degrees C), and return the pie to the oven. Continue baking until the streusel topping is golden brown and the apples are tender, taking an additional 30 to 35 minutes. Cover the pie loosely with aluminum foil to prevent excessive browning.