1 1/4cupsunbleached all-purpose flour,plus more for rolling
1/2teaspooncoarse sea salt,divided
1/3cupplus 1 teaspoon granulated sugar,divided
8tablespoonscold unsalted butter,cut into small pieces
4 1/2teaspoonsarrowroot(or cornstarch)
1large egg,lightly beaten
Sanding Sugar or Turbinado sugar for sprinkling
In a small bowl combine the sour cream, lemon juice and ice water. Set aside.
In a large mixing bowl combine the flour, salt, and 1 teaspoon granulated sugar. Add the butter pieces and beat with a mixer on low until the mixture resembles coarse meal with a few clumps of butter remaining. Gradually add the sour-cream mixture just until combined. The mixture will be crumbly. Test by pinching a small amount of dough together to see if it holds. If it does not hold together add more water 1 teaspoon at a time.
Divide the dough in half and press into two rectangles. Wrap each in plastic wrap and refrigerate until firm, about 1 hour.
Remove the dough from the refrigerator and allow it to rest at room temperature about 10 minutes before rolling. Lightly dust a piece of parchment paper with flour. Using a flour dusted rolling pin, roll out the dough into a 7×14 inch rectangle. Repeat with the remaining dough. Place each rectangle, along with the parchment paper, on a baking sheet and refrigerate 15 minutes.
While the dough is chilling combine the berries, 1/3 cup sugar, arrowroot and 1/4 teaspoon salt in a medium bowl. Gently fold together until combined.
Remove one dough rectangle, still on the parchment paper, from the refrigerator and place it on a flat work surface. Cut the dough crosswise into four 3 1/2 by 7 inch strips.
Mound 1 heaping tablespoon of berry mixture in the center of the bottom half of each strip. Brush the edges with the egg wash and fold the top half over the fruit to enclose. Press firmly to seal and trim bottom edge, leaving the folded top edge uncut. Cut vents in each pie and place 2 inches apart on a baking sheet lined with fresh parchment paper. Transfer the unbaked pies to the freezer. Repeat with the remaining dough rectangle and berry mixture. Freeze the hand pies for 45 minutes for until very firm.
Preheat the oven to 375 degrees. Place racks in the upper and lower thirds of the oven. Lightly brush the pies with the remaining egg wash and sprinkle with the sanding or turbinado sugar. Bake rotating sheets and switching racks halfway through. Bake until pies are golden brown, about 35 minutes. Transfer to a wire rack to cool. Serve warm or at room temperature.
(Recipe adapted from Nora Singley, via MarthaStewart.com)