Preheat the oven to 375ºF.
In a large mixing bowl, toss the sweet potatoes with the oil, salt, and pepper. Put them on a baking sheet and roast until tender, about 1 1/2 hours. Remove from the oven and let cool completely.
In a large mixing bowl, combine the flour, salt, and 2 teaspoons of the granulated sugar. Add the shortening and work it in with your hands until the mixture resembles coarse crumbs. Add the ice water, 1 tablespoon at a time, working it in with your hands. Add only as much as you need to make a smooth ball. Wrap the dough in plastic wrap and refrigerate for at least 30 minutes.
Turn the dough onto a lightly floured work surface. Roll it out into a rectangle about 24 X 8 inches and 1/8 inch thick. With a sharp knife, cut 12 four-inch squares. Set aside.
Peel the potatoes and put the flesh in a large mixing bowl. Add the egg yolk, cane syrup, cinnamon, nutmeg, and a splash of the bourbon and mix well. Place about 1/4 cup of the filling in the center of each pastry square. Fold one corner to the opposite corner to form a triangle. Using the tines of a fork, crimp the edges to seal.
Heat 4 inches of oil in a large, heavy pot or electric fryer to 360ºF. Fry the pies, 2 or 3 at a time, until golden brown, turning them once. Remove the pies and drain on paper towels. Sprinkle with the remaining 2 teaspoons granulated sugar.
Combine the confectioners’ sugar, the milk, and the remaining splash of bourbon in a medium-size mixing bowl and mix until smooth. Drizzle over the hot pies and serve immediately.
Yield: 1 dozen