1.In a large bowl, combine the flour and salt. Place the butter in a small bowl and place both in the freezer for 1 hour. Make a well in the center of the flour. Add the butter to the well and, using a pastry blender, cut it in until the mixture resembles coarse meal. Make another well in the center.
2.In a small bowl, whisk together the sour cream, lemon juice and 1/2 cup ice water and add half of this mixture to the well. With your fingertips, mix in the liquid until large lumps form. Remove the large lumps and repeat with the remaining liquid and flour-butter mixture. Pat the lumps into a ball. Cover with plastic wrap and refrigerate for at least 1 hour.
3.Divide the dough in half. Roll each dough ball into a log and cut into 10 equal pieces. Roll out each piece of dough into a circle of 1/8-inch thickness. Transfer the circles to a parchment-lined baking sheet, and place in the refrigerator to chill for about 30 minutes.
4.Add the peaches into a medium bowl, mix them with 2 tablespoons flour, brown sugar, pinch of salt, cinnamon, nutmeg, bourbon and vanilla.
5.Remove dough from the refrigerator, and let stand at room temperature until just pliable, 2 to 3 minutes. Spoon about 1 to 2 tablespoons filling onto one half of each circle of dough. Quickly brush a little cold water around the circumference of the dough, and fold it in half so the other side comes down over the filling, creating a semicircle.
6.Seal the hand pie, and make a decorative edge by pressing the edges of the dough together with the back of a fork. Repeat process with remaining dough. Place the hand pies back on the parchment-lined baking sheet, and return to the refrigerator to chill for another 30 minutes.
7.Heat oven to 375 degrees. In a small bowl mix egg yolk with 2 tablespoons water. Remove the hand pies from the refrigerator, cut a small slit in each and lightly brush with the egg yolk wash. Sprinkle turbinado sugar generously and cinnamon over the pies, and place pies in the oven to bake. Bake until the hand pies are golden brown and just slightly cracked, about 20 minutes. Remove the pies from the oven, and let stand to cool slightly then transfer to wire rack to cool completely.