Preheat the oven to 425°F. Line a baking sheet (or two, if needed) with parchment paper.

Place the potatoes in a large mixing bowl. Sprinkle both sides with the salt, pepper, and garlic powder. Drizzle with the olive oil and flip the slices so they are evenly coated. Arrange the potatoes in a single layer on the baking sheet(s).

Roast the potatoes on middle rack of oven until they are beginning to brown on the edges, 30-35 minutes. If using two baking sheet, roast on the top and bottom racks, then swap the sheets halfway through the cook time.

Open the oven and sprinkle the slices evenly with Parmesan cheese. Continue roasting until the cheese is melted and golden brown, 7-10 minutes.

Check to see that potatoes are done. Remove from oven or add time as needed.

Sprinkle the potatoes with minced parsley, if desired, and serve immediately.