Sift flour, salt and sugar together in a medium bowl. Add the cubes of butter to the dry mixture. Using your fingers, combine the butter and flour mixture until the butter crumbles to the size of small peas. Add water as needed until the dough comes together. Turn out onto a floured surface, knead the dough into a ball for about 20 seconds. Roll into a circle about ⅛ inch thick and place in a 9-inch pie pan, trim leaving a ½ inch over the edge and crimp. This should make a 9-inch pie crust with extra for decoration. Set in the refrigerator.

Preheat oven to 350°F. Fill a saucepot with water, bring to a boil, add sweet potatoes and cook until tender, approximately 15 minutes. Drain and return to the pot. Using a fork or potato masher, mash the potatoes until smooth. In a separate bowl, combine cinnamon, nutmeg, sugar, lemon juice, milk and eggs. Add the sweet potatoes to the mixture and beat with hand mixer for 2 minutes, until smooth. Pour the pie filling into the crust and brush crust with cream. Bake for 45 minutes. Remove from oven and let rest before serving.