Preheat oven to 400°F. Grease a large, rimmed baking sheet with a thin coat of oil; set aside.
Place the potatoes in a large bowl or Ziploc bag. Add melted butter and toss to coat.
In a separate bowl, stir together flour, Parmesan cheese, Italian seasoning, garlic powder, salt, and pepper. Sprinkle the seasoning mixture over the potatoes and toss to coat.
Spread the potatoes in a single layer on the prepared baking sheet.
Roast the potatoes for 40-50 minutes, or until they’re golden brown and crispy on the outside and fork tender. Stir halfway through so that they brown evenly. Season with additional salt and pepper, to taste. Garnish with chopped fresh parsley, if desired.