Brown Butterscotch Pie
- All-purpose flour, for flouring the work surface
- 1 recipe Flaky Pie Dough
- 1 vanilla bean, split lengthwise, seeds scraped and reserved and pod reserved (or 1 teaspoon vanilla extract)
- 2 cups whole milk
- 1 cup heavy cream
- 4 tablespoons unsalted butter (1/2 stick)
- 3/4 cup packed dark brown sugar
- 9 large egg yolks
- 3 tablespoons cornstarch
- Heat the oven to 350°F and arrange a rack in the middle. Lightly flour a work surface and roll the dough out into a round approximately 12 inches in diameter and 1/4 inch thick. Line a 9-inch pie plate with the dough and trim off the excess. Pierce the bottom of the crust all over with a fork, line it with a piece of parchment paper or aluminum foil, and fill it with pie weights or dried beans.
- Bake until the crust starts to set, about 15 minutes. Remove the pie weights and parchment paper and continue to bake until the crust is dry and slightly brown, about 10 to 15 minutes more. Remove to a wire rack and set aside.
- Combine the vanilla seeds and pod (or vanilla extract, if using), milk, and cream in a small saucepan and bring to a simmer over medium-high heat. Remove from the heat.
- Meanwhile, melt the butter in a large saucepan over medium heat. Add 1/2 cup of the brown sugar, stir to combine, and cook, stirring often, until the mixture bubbles and there is a toasted smell (the butter should be brown but not burnt), about 5 minutes. Carefully whisk in the hot milk mixture and remove the saucepan from the heat to cool slightly, about 5 minutes. Remove and discard the vanilla pod.
- In a large bowl, whisk together the remaining 1/4 cup of brown sugar, egg yolks, and cornstarch until well blended and the whisk leaves a trail when lifted out of the mixture, about 3 minutes. Scrape down the sides of the bowl with a rubber spatula.
- While whisking constantly, slowly pour a third of the milk mixture into the egg yolk mixture and whisk until well combined. Add the egg mixture back to the remaining milk mixture and place the saucepan over medium-low heat. Cook, constantly scraping the bottom of the saucepan with a rubber spatula, until the mixture coats the back of a spoon, about 7 to 10 minutes; set aside.
- Pour the mixture into the pie crust and bake until the edges are set but the middle still jiggles slightly, about 25 to 30 minutes. Place the pie on a wire rack and let it cool completely, about 2 hours. Serve at room temperature or cold.