Preheat oven to 425 degrees. Line a baking sheet with parchment paper and spray well with olive oil.
Place potatoes in a large bowl and toss with olive oil, rosemary , garlic powder and salt. Arrange in a single layer on baking sheet and cook for 8 minutes. Flip and cook for 5 to 8 more minutes, watching towards the end to make sure they do not burn.