Prepare the Crust First:

1. In a large bowl for a food processor, combine the flour, sugar, buttermilk powder, and salt.
2. Add the cold butter and pulse until the dough is crumbly.
3. Mix in the lemon zest and apple cider vinegar.
4. Sprinkle ice water over the mixture 1 Tbsp. at a time while and pulse to mix.  After adding 3 Tablespoons of water, gather the dough and form a bowl.  If the dough crumbles, add more water.
5. Flatten into a disk shape, wrap in cling wrap, and chill in the refrigerator for 1 hour.
6. Preheat the oven to 425 degrees.

Prepare the Filling:

1. Whisk together the sugar, ClearJel or corn starch, nutmeg, salt, lemon juice, peach jam/preserves, vanilla extract, light brown sugar, cinnamon, and nutmeg.
2. Very gently mix in the peaches and set aside.

Prepare the Crust:

1. After the dough has chilled, roll it out into a 12″ circle on a well-floured board or cooking surface.  Parchment paper under the dough is also very helpful.
2. With a knife or pizza wheel, trim off the excess dough around the edges to make a nice circle.
3. Line a baking pan with parchment paper and dust with a little bit of flour.
4. With a huge spatula, very gently move the dough to the parchment-lined baking pan, being ever so careful not to tear the dough.
5. Using a slotted spoon, fill in the center (only) of the dough with the peaches laid out in a decorative circular pattern.  Do not use all of the juice, the crust will not bake through on the bottom and you’ll have a soggy mess.  Leave 1-1/2 to 2″ of dough uncovered with peaches . . . you need this dough to fold over the peaches.
6. Carefully fold the edges of the dough over the peaches, leaving a big hole in the middle.   Don’t cut any excess dough off, but rather fold the dough over and over.
7. Place the pieces of cold butter on top of the peaches.
8. Make the egg wash with the egg and water; brush all over the crostata.  Generously sprinkle with coarse sugar.  Blow a kiss to it!
9. Bake the crostata for 20 minutes without any cover.
10. After 20 minutes have passed, loosely cover the crostata with aluminum foil and bake for another 25 – 30 minutes (keep an eye on it though).  This may seem like a large range, but every oven is different, so it is important to check on it until the crust is golden brown and the peaches are bubbling.
11. Remove from the oven, place on a baking rack, and allow the crostata to set a bit for 20 minutes to allow the filling to set and thicken.
12. While still warm, carefully brush the top of the peaches with some peach jam for a light glaze.
13. Dust with powdered/confectioners sugar.  Serve warm ‘ala mode’ with a scoop of vanilla ice cream.
14. Enjoy and Buon Apetito!!