1) To make the crust: Put the flour in a bowl, or in the work bowl of a food processor. Add the cream cheese, salt, and buttermilk powder. Mix together until everything is evenly crumbly. If you're using a food processor, just a few quick pulses are all you'll need.
2) Cut the cold butter into pieces and work it into the flour, leaving some visible pieces.
3) Sprinkle the dough with the cold water and toss. Squeeze the dough to determine if it holds together. If it's too dry, add water 1 tablespoon at a time, using just enough so the dough will hold together.
4) Divide the dough in two pieces, one slightly larger than the other. if you have a scale, one piece should be about 9 ounces; the other about 10 ounces. Flatten each piece of dough into a disk, wrap well, and refrigerate for 30 minutes or longer.
5) Remove the larger piece of dough from the refrigerator, and roll it into a 13" circle. Place it in a 12" shallow pizza pan, or onto a parchment-lined baking sheet. The parchment is there to catch any spills and simplify cleanup; if you don't have it, there's no need to grease your pan.
6) Spread the Baker's Cinnamon Filling mixture atop the crust. If you're using sugar and cinnamon, simply sprinkle it evenly atop the crust.
7) Arrange the apples in concentric rings atop the filling. Or, if you don't feel like being that fussy, simply spread the apples over the crust.
8) Sprinkle the apples with a dash of salt, and drizzle with the lemon juice. Scatter the bits of butter over all.
9) Remove the other piece of dough from the refrigerator, and roll it into a 12" circle. Place it atop the apples. Bring the edge of the bottom crust up over the top, pressing to seal.
10) Brush the crust with milk, and sprinkle with coarse white sparkling sugar, if desired. Cut a dime-sized hole in the middle; or cut several 1" slits across the top, for steam to escape.
11) Bake the pie in the preheated 425°F oven for 15 minutes. Reduce the heat to 375°F, and continue to bake for an additional 25 to 35 minutes, or until the crust is golden brown and you can see some filling bubbling through the slits in the top.
12) Remove the pie from the oven, and wait about an hour before cutting into wedges and serving.
Yield: one 12" pie.