Step 1

Combine flour, sugar, and salt in a food processor by pulsing a few times. Add the very cold butter cubes (2 sticks, equivalent to 1 cup) and pulse a few times until a pea-size coarse meal forms. Add the buttermilk and run the food processor continuously for several seconds until a dough forms. At first, it will look like it's not coming together but it will.

Step 2

Transfer onto a non-floured clean surface. Press to form a dough. Divide the dough in half. Roll each half into balls and flatten into thick disks. Wrap each disk with plastic wrap and chill in the fridge for at least 1 hour or overnight. Before using, let it sit on the counter for 15 minutes to slightly soften it.

Step 3

Peel apples and cut out the core. Then cut into 1/4 inch slices. They should all be cut to the same size for even cooking.

Step 4

In a large deep skillet or Dutch oven over medium heat, melt 1 tablespoon unsalted butter and add the sliced apples, brown sugar, granulated sugar, cinnamon, nutmeg, allspice, salt, lemon juice and lemon zest. Cook, stirring for about 10-15 minutes until apples have slightly softened but not lost their shape.

Step 5

Sift and sprinkle 1-2 tablespoons cornstarch and mix (start with 1 tablespoon and add more if needed. The amount of cornstarch depends on the amount of juices released by the apples). Bring to a simmer and cook for an additional 3-5 minutes until juices thicken. If not thick enough, add more cornstarch little by little, stirring. Note: sifting the cornstarch beforehand prevents clumps from forming.

Step 6

Set aside and let cool at room temperature. Tip: to speed up the cooling process, transfer the apple filling to a large shallow bowl or a large pan.

Step 7

After the filling has cooled down, preheat oven to 400 degrees F.

Step 8

Cut remaining 1 tablespoon of cold butter into small cubes. Set aside.

Step 9

Get a 9-inch round pie pan ready. Roll out the dough to a 12-inch circle using a rolling pin on a floured surface to about ¼ inch thick. Repeat for the second disk.

Step 10

Transfer dough to a 9-inch pie pan. Fill with the cooled apple pie filling and dot with the remaining 1 tablespoon butter cut into small cubes. Cover the pie with the second rolled out dough. Trim any overhang or excess dough. Seal edges with a fork or with your fingers. Make a few slits at the top to let the steam escape. Alternatively, you can make a lattice pattern. For instructions, see the “How to Make a Lattice Pie Crust” above.

Step 11

If you made a lattice top, refrigerate the pie for about 15-20 minutes. If you did not, skip this step.

Step 12

Make the egg wash by whisking the egg with heavy cream or milk. Brush the pie dough with egg wash and sprinkle with coarse sugar if desired.

Step 13

Place pie on a large baking sheet and bake for 25 minutes at 400 degrees F. Remove pie from oven and put a pie crust shield or cover edges with foil. Lower oven temperature to 375 F and bake for an additional 30-35 minutes until golden brown and bubbly.

Step 14

Let it cool on a wire rack for 3 hours before serving. Trust me, if you cut into it before it has cooled down, it will fall apart (been there, done that). Enjoy!