Preheat your oven to 400°F.
Slice each potato in half lengthwise. Spread 1/2 tablespoon of butter on the cut side of each half, then sprinkle evenly with garlic powder and salt. Reassemble the halves to make whole potatoes.
Wrap each potato securely in aluminum foil, ensuring the foil is tightly sealed around the potato.
Place the foil-wrapped potatoes directly on the middle oven rack and bake for 40 to 60 minutes, or until they are tender when pierced with a fork.