To make the crust: Add the flour to the bowl of a stand mixer (or just a large mixing bowl if making by hand).

In a separate bowl, add the sourdough discard and water and stir to combine completely. Set aside.

Cut the butter into small cubes, the smaller the cubes, the flakier the crust. At least cut the sticks into 4 and small cubes from there.

Add the cubed butter into the mixing bowl with the flour and mix on low until combined and the mixture looks like wet sand. (If using your hands, squish together with your fingers until it looks like wet sand.)

Immediately add the sourdough discard and water and continue to mix to combine until it’s just incorporated, so not over mix. (If using your hands, mix until combined into a pie dough.)

Divide the dough into 2 portions for top and bottom, top should weigh about 200 grams and bottom should weigh about 300 grams. Form into disks and wrap with plastic wrap. Refrigerate for at least 4 hours or overnight.

Preheat the oven to 350°F. To make the filling: Add the brown sugar, sourdough discard, cornstarch, cinnamon, and nutmeg. Set aside.

Slice the apples, leaving skins on (or remove if you prefer!). Add to the filling and toss with your hands to combine completely.

Grease a 9-inch pie pan well with butter. Remove the pie dough from the fridge. Remove the plastic wrap and place on a floured surface. First, roll out the large disk to ¼-inch thick, it should be about 11-inches in diameter.

Place the pie dough into the pie pan, and press lightly to form against the pan. It should be large enough that the dough folds right over the top. Roll out the smaller disk to ¼-inch thick, it should be about 9-inches in diameter. Set aside.

Add the filling into the pie pan and spread evenly.

Place the smaller pie dough on top, crimp and fold over the edges of the dough to seal the top and bottom together. Flute the edges.

Using a pastry brush, brush the dough with the cream topping. Sprinkle it with Turbinado sugar. Then make 4 vent holes in the top.

Bake for 1 hour and 15 minutes, or until lightly browned. Turn up the oven to 400°F and bake for an additional 5 to 15 minutes or until golden brown to your liking. (If you are baking at high altitude, be sure to check the Notes at the bottom of the recipe for high altitude baking instructions).