Preheat your oven to 425°F (220°C) and line a large baking sheet with parchment paper.
In a large mixing bowl, combine the halved baby potatoes, pesto, olive oil, garlic powder, salt, and black pepper. Toss until the potatoes are evenly coated.
Spread the coated potatoes in a single layer on the prepared baking sheet.
Roast in the preheated oven for 25-30 minutes, or until the potatoes are golden brown and fork-tender, stirring halfway through for even cooking.
Remove the potatoes from the oven and sprinkle the grated Parmesan cheese over the top. Return to the oven for an additional 5 minutes, or until the cheese is melted and slightly crispy.
Garnish with fresh basil leaves if desired and serve warm.