Directions

1. Fill a one cup liquid measuring cup with water, and drop in a few ice cubes; set it aside. Dice one stick of unsalted butter into 1/2-inch pieces and place into the freezer. In a food processor add 1 1/4 cups flour, 1 1/2 teaspoon of sugar, and a 1/2 teaspoon of salt. Press the pulse four times to mix. Sprinkle the butter cubes over the flour and pulse 12 times until butter pieces are the size of tiny peas. Turn on food processor and add 1/4 cup of ice water through the feeding tube. Once water has been incorporated, dump mixture into a large bowl and form a disk. Let the dough chill in the fridge overnight.
   
2. Place sweet potatoes in a large saucepan. Cover them with water, then bring to a boil on the stovetop. Boil until super soft about 45 minutes.
   
3. Meanwhile, on a floured work surface roll out the chilled dough. Turn the dough about a quarter turn after every few rolls until you have a circle 13 inches in diameter. Carefully place the dough into a 9-inch pie dish. Tuck it in with your fingers, making sure it is completely smooth. Fold the excess dough back over the edge and use your hands to mold the edge into a nice thick rim around the pie. Use your fingers to flute the edges. Chill the dough in the freezer for at least 15 minutes as you work on the filling.
   
4. Preheat oven to 350°F. Drain the water from the pan and run the potatoes under very cold water. Peel the skin off and place into a bowl. Mash with potato masher until smooth.
   
5. Fit mixer with a paddle attachment, beat the 1/2 cup softened butter and brown sugar on medium-high speed until fluffy. Add sweet potatoes and beat until combined. Add 1/2 cup heavy cream, kahlua, 2 eggs, 2 tablespoons, flour, 1 teaspoon vanilla, cinnamon, nutmeg, cloves, ginger, and 1/8 teaspoon salt and beat on high speed until smooth and combined.
   
6. In a small bowl, beat one egg and brush egg wash over the top of the crust. Spread filling over top of crust.
   
7. Bake for 55-60 minutes or until the center of the pie is only slightly jiggly. A toothpick inserted into the center of the pie should come out mostly clean. During bake time, if you find the edges of the pie crust are browning too quickly, apply a ring of aluminum foil to protect it.
   
8. Remove finished pie from the oven. Place on a wire rack to cool completely or for at least 2 hours. In the bowl of a standing mixer with whisk attachment add 1/2 cup heavy cream, powdered sugar, and 1/2 teaspoon vanilla. Whip until stiff peaks. Serve pie with whipped cream.