For the Crust:
- 1/2 cup (4 ounces) cold unsalted butter, cut into small cubes
- 1 1/2 cup all-purpose flour
- 2 teaspoons granulated sugar
- 1/2 teaspoon salt
- 1/3 cup cold buttermilk
For the Filling:
- 2 cups mashed cooked sweet potatoes, from 2 medium sweet potatoes
- 3/4 cup packed brown sugar
- 1 1/4 teaspoon ground coriander
- 1/2 teaspoon freshly grated nutmeg
- 1/2 teaspoon cinnamon
- 1/4 teaspoon salt
- 1/4 cup (2 ounces) unsalted butter
- 1 1/4 cup (10 ounces) evaporated milk, divided
- 1/3 cup granulated sugar
- 3 large eggs
- 1 tablespoon pure vanilla extract
- To make the pie crust, in a medium bowl, whisk together flour, sugar, and salt. Add cold, cubed butter and, using your fingers (or a potato masher), 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.
- Preheat the oven to 375 degrees F. Place a rack in the upper third of the oven.
- To make the filling, first peel the sweet potatoes. Dice the sweet potatoes into large, 3-inch chunks. Place potato pieces in a large pot and cover with cool water. Place over medium high heat and bring to a boil. Reduce heat to medium and simmer until the potatoes are tender throughout, about 20 minutes. Test the doneness of the potatoes using a thin knife. If the knife meets any resistance, simmer the potatoes a bit longer.
- Drain into a colander.
- In the same large pot place cooked potato pieces, the packed brown sugar, all of the spices, salt, butter, and half of the evaporated milk. Cook on low flame, using a potato masher to mash the potatoes and they cook. Simmer for about 5 minutes. Make sure that the mixture is as smooth as possible. I used an immersion blender to completely smooth the mixture. Once mixture is smooth and fragrant, remove from fire and let cool in pot.
- In a medium bowl, whisk together the remaining evaporated milk, granulated sugar, eggs, and vanilla extract. Whisk well. Pour the egg mixture into the warm sweet potato mixture.
- Pour the prepared filling into the pie crust. Place on a baking sheet and bake for 10 minutes at 375 degrees F. Reduce the heat to 325 degrees F and cook until cooked through, about 45 to 50 minutes.
- To test the pie for doneness lightly shake the baking sheet. If the center of the pie has a wavy jiggle it needs more time in the oven. If the center of the pie has a lighter, more structured jiggle, it’s done!