3 tablespoons ice water, plus more if needed
1 large egg yolk, lightly beaten
FILLING AND TOPPING:
2 cups apple cider
1 cup sugar
1/4 cup water
2 tablespoons unsalted butter
2 large eggs at room temperature, separated
1 cup creme fraiche
1 to 2 tablespoons whipping cream, half-and-half or whole milk
For crust, combine flour, butter and salt in a food processor. Pulse until mixture resembles coarse meal. Add ice water and egg yolk. Process until moist clumps form, adding more water by teaspoonfuls, if dough is dry.
Gather into a ball and flatten into a disk. Wrap in plastic and chill at least 30 minutes or longer. (Dough can be made 1 day ahead; keep chilled.) Roll dough out on a lightly floured surface into a 12-inch round, then transfer to a 9-inch pie plate.
Fold in overhanging dough to form a high-rising border and flute the edges. Refrigerate dough at least 30 minutes while you prepare the filling. (Pie shell can be prepared 1 day ahead; cover with plastic wrap and keep refrigerated.) Arrange a rack at center position and preheat oven to 450 degrees.
For filling, have ready a 1-cup glass measuring cup. Put cider in a large saucepan and place over medium high heat. Cook until cider reduces to ½ cup. Time should be about 15 to 20 minutes but can vary depending on type of pan used, so watch carefully.