This is a simple and delicious recipe for sweet potato stick pies using frozen pie crust and sweet potatoes. Heat the sweet potatoes in the microwave, mash them, and mix with butter and sugar to make a filling. Place the filling between the pie crusts, twist them, sprinkle with egg yolk and black sesame seeds, and bake in the oven. It's a cute-looking snack with the sweetness of fluffy sweet potatoes. Pumpkin can also be used as a substitute.