Mix ⅓ cup of the ice water and sour cream together in a small bowl until combined.
Process the flour, sugar, and salt together in a food processor until combined.
Scatter the butter pieces over the top and pulse the mixture until the butter is slightly larger than the size of large peas (about 5-8 quick pulses)
Pour half the sour cream mixture over the flour mixture and pulse until incorporated, about three pulses. Repeat with the remaining sour cream mixture. Pinch the dough with your fingers; if the dough feels dry and doesn’t hold together, sprinkle 1 to 2 tablespoons more ice water over the mixture and pulse just until the dough forms large clumps and no dry flour remains (3-5 pulses).
Divide the dough into 2 even pieces. Turn each piece of dough onto a sheet of plastic wrap and flatten each into a disk. Wrap each piece tightly in plastic wrap and refrigerate for 1 hour up to 3 days. Before rolling the dough out, let it sit on the counter to soften slightly, about ten minutes if chilled for one hour, at least 30 minutes if chilled overnight. When ready to roll out lightly dust your counter or rolling surface with flour and roll to about a 12” disc.
Carefully set the dough in the pie pan and gently press it down and to the sides. Trim the edges a little longer than the edge of the pie pan. Crimp dough edges with fingers or a fork. Pie crust doesn't need to be baked before filling.