Preheat the oven to 425 degrees Fahrenheit (218 degrees Celsius).
Line a large rimmed baking sheet with parchment paper or a silicone baking mat.
In a large bowl, combine the cubed potatoes, olive oil, salt, pepper, rosemary, and garlic powder.
Toss the ingredients until the potatoes are evenly coated with oil and seasonings.
Spread the potatoes onto the prepared baking sheet in a single layer, ensuring they are not overcrowded.
Roast for 30 to 35 minutes, tossing the potatoes with a spatula halfway through the cooking time.
Remove from the oven once the potatoes are golden brown and fork-tender.
Serve hot.