Preheat the oven to 425°F (220°C).
Wash the 8–10 large carrots, peel if desired, trim the ends, and cut them into even-sized pieces so they cook evenly. Arrange the carrots in a single layer on a rimmed baking sheet. Sprinkle with salt and pepper.
In a small bowl combine ¼ cup melted butter, 1 tablespoon olive oil, 3 cloves chopped garlic, and 1 tablespoon grated Parmesan cheese.
Pour the butter mixture over the carrots and toss (on the pan or in a bowl) until the carrots are evenly coated.
Roast the carrots in the preheated oven for 20–25 minutes, turning once halfway through, until they are browned at the edges and tender when pierced with a fork.
Remove from the oven and top with freshly shredded Parmesan cheese and parsley. Serve immediately.