Preheat your oven to 400 degrees F.
Line a baking sheet with aluminum foil and spray it with cooking spray. Set aside. You may need two baking sheets depending on the number of potatoes you use.
Fill a large pot with 1-2 quarts of water, add 1 teaspoon salt, and bring to a boil. Then reduce to a gentle simmer.
Peel the potatoes and slice them about 1/2 inch thick. Place the slices into the simmering water and cook for 3-4 minutes. The potatoes should be slightly soft but still firm in the center. Drain and run cold water over the slices to cool them slightly.
Using a small heart-shaped metal cookie cutter, cut out as many hearts as possible from the slices. Place any leftover potato scraps in a bowl of water to use later for mashed potatoes if desired.
In a separate bowl, combine the olive oil, salt, pepper, garlic powder, rosemary, and paprika. Pour this mixture over the potato hearts, toss gently, and let them sit for about 5 minutes.
Arrange the potatoes on the prepared baking sheet and roast in the oven for 22-25 minutes, flipping them over halfway through. If your oven has a broiler, broil the potatoes for an additional 5 minutes to achieve a golden brown color, watching carefully to prevent burning.
Serve the roasted potato hearts with ketchup for dipping or sprinkled with fresh Parmesan, if desired.