Silky Sweet Potato Pie

Ingredients

• 16 ounces peeled, roughly diced sweet potatoes , from 2 medium sweet potatoes
• 1 vanilla bean, split and scraped, seeds reserved for whipped cream topping
• 2 or 3 cinnamon sticks
• 1 whole nutmeg
• 26 ounces milk , any percentage will do
• 6 ounces heavy cream
• 7 ounces white or lightly toasted sugar
• 1 tablespoon ground cinnamon
• 1 teaspoon freshly grated nutmeg
• 1/2 teaspoon Diamond Crystal kosher salt; use half as much if iodized
• 1/2 ounce vanilla extract
• 3 large eggs
• Old-Fashioned Flaky Pie Dough, prepared as for a blind-baked pie
• Brown Sugar Whipped Cream

Directions

1. In a 3-quart stainless steel saucier, combine sweet potatoes, empty vanilla pod, cinnamon sticks, whole nutmeg, milk, cream, and sugar. If you have a scale, write down the weight of the saucier and combined ingredients so you can precisely measure the reduction.
2. Bring to a boil over high heat, then adjust to medium-low and maintain a gentle simmer (higher heat may cause the milk to curdle). Scrape frequently with a flexible spatula to prevent milk solids from building up around the side, and simmer until sweet potatoes are fall-apart tender and dairy has condensed into a thick sauce, about 55 minutes. The saucier should weigh 19 ounces (535g) less than when you started. (Alternatively, total volume, including cooked sweet potato, should be 3 2/3 cups when finished.)
3. Adjust oven rack to lower-middle position and preheat to 350 degrees F (177 degrees C). Remove vanilla bean and spices from saucier and purée sweet potato and dairy mixture with an immersion blender until smooth. (If needed, transfer to a smaller container to avoid splashing.) Whisk in ground cinnamon, grated nutmeg, salt, and vanilla, followed by eggs. If you like, strain through a fine-mesh strainer before pouring into prepared pie crust.
4. Bake pie until gently set in the middle (with an internal temperature of 195 degrees F or 91 degrees C), about 40 minutes. Cool at least 20 minutes before slicing with a chef's knife, pausing to wipe the blade clean as needed. If desired, serve with dollops of Brown Sugar Whipped Cream. Wrapped in plastic, sweet potato pie will keep up to 3 days at cool room temperature.