Preheat oven to 400°F (200°C).
In a small bowl, mix balsamic vinegar, maple syrup, olive oil, garlic, salt, and pepper.
Place chicken thighs in a baking dish and pour the balsamic mixture over them.
Scatter cranberries around the chicken.
Roast for 35-40 minutes, basting with pan juices halfway through cooking.
Garnish with fresh rosemary before serving.