Preheat the oven to 400°F. Line a sheet pan with parchment paper or foil.
Scrub the sweet potatoes well under cool water and dry them completely.
Prick each potato several times with a fork.
Place the potatoes on the prepared sheet pan with a little space between each one.
Bake for 45 to 60 minutes, turning once halfway through cooking. Check for doneness by inserting a thin knife into the center. It should slide in easily with very little resistance.
Let the potatoes rest for 5 minutes. Cut a slit down the center of each potato and gently press the ends to open them.
Serve hot with your choice of butter, sliced scallions, toasted sesame oil, flaky salt, or furikake.
Notes
Smaller potatoes may be ready in about 40 to 45 minutes. Large potatoes may take 60 to 75 minutes.
Choose potatoes that are close in size so they finish baking at about the same time.
Bake the potatoes uncovered. Wrapping them in foil traps steam and softens the skin.
Furikake can be salty, so taste the potatoes before adding extra salt.