Black-and-Blue Pie with Brown Sugar Crumb

Make the Pie Dough

1. Combine the hot water, brown sugar, vinegar, and salt in a small metal bowl. Stir until the sugar dissolves. Place the liquid in the freezer until very cold, about 20 minutes. Transfer mixture to the refrigerator, and chill until ready to use.

2. Place the flour and 1/2 cup cubed butter in a large bowl. Pinch and smear butter between your fingers. (Processing butter like this creates small leaves of butter that layer in the dough, resulting in a flaky crust.) Once all of the butter chunks have been pinched, grab small handfuls of flour and butter and rub them together between your palms until the mixture resembles uneven pebbles on a sandy beach.

3. Dump the crumbly mixture out onto a clean work surface. Scatter the remaining 1/2 cup cubed butter over the dough. Use the palm of your hand to smear butter as if you were sliding a secret message across a table. Use a bench scraper to gather the shaggy dough, and repeat the smearing process until you have a pile of striated rubble. Larger pieces of butter will create a marbled dough and will melt during baking, causing the water in the butter to evaporate, resulting in flaky pastry pockets.

4. Gather the dough up in a mound, and form a well in the center. Remove the cold liquid mixture from the refrigerator, and pour half into the well. Using your fingertips, slowly bring the dough into the center, combining with the liquid, until the liquid has been incorporated. Gather the moistened dough into a shaggy pile.

5. Slowly pour the remaining half of the liquid onto the pile of dough. Lift the dough from the bottom, and squeeze just until it comes together into a mass. Divide the dough ball in half (about 12 ounces each), and shape each half into a disk. Wrap each disk in plastic wrap, and chill in the refrigerator 2 hours before using. (You only need 1 disk, so if not using the other within 2 days, place it in the freezer.)

Make the Pie

1. Combine the flour, butter, oats, brown sugar, and 1 teaspoon of salt in a medium bowl. Pinch and smear butter between your fingers until the mixture is sandy and the butter is evenly incorporated. Chill until ready to use.

2. Preheat the oven to 375°F with one of the racks in the lower third of the oven. Unwrap 1 of the chilled dough disks and place on a lightly floured work surface. (If dough has been chilled for more than 8 hours, let stand at room temperature for 10 to 15 minutes.) Roll it into a 12-inch round.

3. Transfer it to a 9-inch pie pan with a lip; use your fingertips to relax the dough into the shape of the pan. Trim the dough, leaving a 1-inch overhang around the edge of the dish. Fold the edge of the dough under itself. Use your thumb and forefinger to crimp the edges, pressing into the pan and ensuring the dough extends to the outer edge of the dish. (This anchors the pie crust, which results in a proud crown of crust after baking.) Freeze the dough, uncovered, until very cold, about 20 minutes.

4. Line the crust with heavy-duty aluminum foil, leaving 1 1/2 inches of overhang. Trace your fingertips over the foil overhang, gently pressing into the crimp. Fill foil-lined crust with pie weights or dried beans. Bake in the preheated oven until the crust is light golden around the edges, 20 to 25 minutes. Remove pie weights and foil; prick the bottom of the crust all over with a fork. Return to the oven, and bake at 375°F until the bottom of the crust is lightly browned, 6 to 8 minutes. Transfer to a wire rack to cool completely, about 30 minutes. While the crust cools, reduce the oven temperature to 350°F.

5. Toss together the berries, granulated sugar, cornstarch, lemon juice, and remaining 1/4 teaspoon salt in a large bowl until the berries are coated. Squeeze about a handful of berries, breaking them open. Stir in the juices and smashed fruit. (This helps to create a sauce by introducing a small amount of berry juices to the filling before baking.)

6. Spoon the berry filling into the cooled crust. Sprinkle with the chilled crumb topping, sprinkling all the way to the edge of the crust. Place the pie in the oven. (If desired, slide an aluminum foil–lined baking sheet onto the oven rack below the pie to catch any drips.) Bake at 350°F until the filling is bubbling, about 1 hour and 30 minutes, shielding the edges with foil after 25 minutes to prevent excess browning, if necessary.

7. Transfer the pie to a wire rack, and let cool completely, about 3 hours. Serve the pie slices with cold heavy cream for drizzling.

Make Ahead

Pie dough tightly wrapped in plastic wrap will keep in the refrigerator up to 2 days.