Preheat oven to 425 degrees.
Line a baking sheet with aluminum foil.
Spread carrots in a single layer on the baking sheet. Drizzle with olive oil, and sprinkle with garlic salt and pepper.
Toss carrots with your hands until they are evenly coated with oil, salt and pepper.
Roast carrots for 20 minutes if you want crisp-tender carrots, or 30 minutes for softer carrots with a deeper roasted flavor. While carrots are baking, combine the balsamic vinegar and balsamic glaze in a small bowl.
Remove carrots from oven. Drizzle balsamic mixture over the carrots, and stir gently with a wooden spoon or silicone spatula until carrots are evenly coated.
Return carrots to oven and bake for 3 minutes.
Remove carrots from oven and stir a second time to distribute glaze evenly. Bake for 3 more minutes.
Remove carrots from oven, transfer to serving dish, and sprinkle with parsley.