Peel, wash and roughly chop the sweet potatoes. Then cook in salted water for about 20 minutes. Then drain the water and let the sweet potatoes cool down. Mash the cooled sweet potatoes with a potato masher or a press into a pulp, then knead with the other ingredients (except for the clarified butter) to form a smooth dough. The dough should no longer stick, otherwise add a little more flour. Shape the dough into rolls that should be approx. 3 cm in diameter. Cut pieces as thick as a finger on a floured work surface and shape them into potato noodles in the palms of the hands. Meanwhile, bring salted water to the boil in a large saucepan, turn the heat down to medium heat and let the potato noodles simmer in portions for about 5 minutes each, then remove with a ladle and drain in a sieve. The potato noodles are then fried in clarified butter in a coated pan over a medium heat until they are golden brown, turning several times. The Schupfnudeln taste best fresh from the pan with a hearty bacon and sauerkraut, served with a vegetable pan or simply sprinkled with a little Parmesan.