• Place the diced butter in the freezer for 10 to 15 minutes.
  8 tablespoons unsalted butter
• Mix ice water and the sour cream in a small bowl until combined.
  2 tablespoons plus 2 teaspoon ice water, 1½ tablespoons sour cream
• Process the flour, sugar and salt together in a food processor until combined.
  1¼ cups unbleached all purpose flour, ½ tablespoon sugar, ½ teaspoon table salt
• Scatter the butter pieces over the top and pulse the mixture until the butter is the size of large peas, about 10 pulses.
• Pour half of the sour cream mixture over the flour mixture and pulse until incorporated, about 3 pulses. Repeat with the remaining sour cream mixture.
• Pinch the dough with your fingers. If the dough feels dry and does not hold together, sprinkle ½ to 1 tablespoon more ice water over the mixture and pulse until the dough forms large clumps and no dry flour remains, 3 to 5 pulses.
• Wrap dough in plastic wrap, forming into a 4-inch disk before refrigerating.

To Par-Bake or Blind Bake the Crust:

• Roll the chilled dough on a floured surface into a 12-inch circle.
  
• Fold the dough into fourths and transfer to a 9-inch pie plate. Fit the crust into the pie plate and trim the edges to leave a 1 inch overhang. Fold the dough under itself and crimp.
  
• Cover and chill for at least 30 minutes. Meanwhile, adjust an oven rack to the middle position and preheat the oven to 375°F.
• Prick the chilled dough all over with a fork, then line with parchment paper and fill with pie weights, ensuring the weights fill the pan fully and evenly.
  
• Place the pan on a parchment paper-lined baking sheet and bake for 20 to 25 minutes, until edges are golden, then carefully remove the parchment and weights.
  
• Return the crust, still on the baking sheet, to the oven for 5 to 10 minutes, until the bottom looks matte. To blind bake, keep baking the crust until it is completely golden brown. You can add a ring of aluminum foil around the edges if they brown quicker than the center.
  
• After the crust is finished baking, transfer the pie plate to a wire rack and proceed with your pie recipe.