1/2 cup (1 stick, 4 ounces) cold unsalted butter, cut into small chunks
1/4 cup plus 1 to 2 tablespoon cold buttermilk
For the Filling
6–7 ripe but firm pears, any variety, peeled and sliced, about 5 cups sliced
juice of 1 lemon
2 tablespoons granulated sugar
2/3 cup lightly packed brown sugar
2 tablespoons cornstarch or instant tapioca
1/2 teaspoon ground ginger
1/4 teaspoon allspice
1/4 teaspoon ground cardamom
pinch freshly grated nutmeg
pinch of fresh cracked black pepper
1/2 teaspoon kosher salt
3 tablespoons bourbon
2 dashes bitters
1 teaspoon pure vanilla extract
For the Crumble
3/4 cup all-purpose flour
3/4 cup old-fashioned oats
2/3 cup granulated sugar
large pinch of salt
6 tablespoons cold unsalted butter, cut into small chunks
1/2 cup coarsely chopped pecans
To make the crust, in a medium bowl, whisk together flour, sugar, and salt. Add cold, cubed butter and, using your fingers, work the butter into the flour mixture. Quickly break the butter down into the flour mixture, some butter pieces will be the size of oat flakes, some will be the size of peas. Create a well in the mixture and pour in the cold buttermilk. Use a fork to bring to dough together. Try to moisten all of the flour bits. Add a bit more buttermilk if necessary, but you want to mixture to be shaggy and not outwardly wet.
On a lightly floured work surface, dump out the dough mixture. It will be moist and shaggy. That’s perfect. Gently knead into a disk. Wrap the disk in plastic wrap and refrigerate for 1 hour. Allowing the dough to rest in the refrigerator will help rechill the butter and distribute the moisture.
To roll out the pie crust, on a well floured surface, roll the crust 1/8 inch thick and about 12 inches in diameter. Transfer it to a pie pan. Trim the edge almost even with the edge of the pan Fold the edges under and crimp with your fingers or a fork. Cover it with plastic wrap and refrigerate it for a minimum of 30 minutes and a maximum of 3 hours.
To make the filling, in a medium bowl toss together sliced pears, lemon juice, and granulated sugar. Allow to macerate for 20 minutes. Add brown sugar, cornstarch or tapioca, spices, pepper, salt, bourbon, bitters, and vanilla. Toss to evenly coat the pears in the mixture but try to be gently enough as to not bruise the pears too much.
To make the crumble, in a medium bowl (yea… we’re using a lot of medium bowls), whisk together flour, oats, sugar, and salt. Add the cold butter chunks and, using your fingers, work the butter into the flour mixture. Quickly break the butter down into the mixture until well incorporated. Some butter bits will be the size of peas, and smaller. Add the pecans and toss to combine.
To Assemble the Pie
Place a rack in the center of the oven and preheat oven to 400 degrees F. Line a baking sheet with parchment paper. Set aside.
Remove the pie crust from the refrigerator. Toss a handful (about 1/2 cup) of the topping mixture into the pear mixture, toss. Dump the fruit mixture into the pie crust. Top generously with topping mixture. Place on the prepared baking sheet and place in the oven. It’s important to use the middle rack because if the pie is too close to the top of the oven, the pecans will burn quickly.
Bake for 20 minutes then reduce the heat to 375 and bake for another 30 minutes until golden brown and bubbling.
Remove from the oven and cool for 3 hours before serving. This will allow the juices to thicken and rest.
Serve in generous slices with vanilla ice cream or whipped cream.