Preheat oven to 425°F. Grease or line a large baking sheet for easy cleanup.
In a small bowl, combine olive oil and garlic powder. Add the brussels sprouts and carrots into the pan and toss with oil until evenly coated. Arrange the vegetables in an even layer with the flat sides facing down. Roast for 15-20 minutes.
Remove from the oven and toss with balsamic vinegar and maple syrup. Return to the oven for 5 more minutes.