Crust
1 cup all-purpose flour
1 tablespoon cornstarch
1 tablespoon sugar
1 teaspoon kosher salt
1 stick unsalted butter, cut into 1/2-inch dice and chilled
3 tablespoons cold milk
1 teaspoon apple cider vinegar


Filling and Topping
2 cups apple cider
1 cup sugar
1/2 cup sour cream
1/4 teaspoon salt
4 large eggs
1 cup heavy cream
1/2 teaspoon cinnamon

In a food processor, combine the flour, cornstarch, sugar and salt. Add the butter and pulse in 1-second bursts until the mixture resembles coarse meal. Combine the milk and vinegar and drizzle it on top of the flour mixture. Pulse in 1-second bursts until the dough just comes together. Turn the dough out onto a work surface, gather up any crumbs and pat into a disk. Wrap in plastic and refrigerate until chilled, about 30 minutes.

On a floured work surface, roll the dough into an 11-inch round, a scant 1/4 inch thick; ease it into a 9-inch glass or ceramic pie plate. Trim the overhanging dough to 1 inch and fold it under itself. Crimp decoratively and chill the crust until firm, about 15 minutes.

Preheat the oven to 425° F. Line the crust with parchment paper and fill with pie weights or dried beans. Bake in the lower third of the oven for about 15 minutes, until the crust is barely set. Remove the parchment and pie weights. Cover the edge of the crust with strips of foil and bake for about 10- 15 minutes longer, until the crust is just set but not browned. Press the bottom of the crust lightly to deflate it as it puffs; let cool. Lower the oven temperature to 350°.

In a medium saucepan, boil the cider until it’s reduced to 1/2 cup, about 10-15 minutes. Transfer to a bowl and let cool. Whisk in 3/4 cup of the sugar, the sour cream and salt, then whisk in the eggs.

Pour the custard into the pie shell without removing the foil strips. Bake the pie in the lower third of the oven for 35 to 40 minutes, until the custard is set around the edge but the center is slightly jiggly. Let the pie cool completely.

In a medium bowl, using an electric mixer, beat the heavy cream with the remaining 1/4 cup of sugar and the cinnamon until firmly whipped. Mound the whipped cream on the pie, cut into wedges and serve.

The pie is best eaten the day it is made, but it will keep for up to two days in the fridge. If you plan on making it in advance, do not top with the whipped cream until you are ready to serve.