Preheat oven to 350. Melt butter in a large ovenproof skillet over medium heat. Stir in sugar, ground cinnamon, and cinnamon sticks. Place apples in skillet, cut sides down.
Transfer skillet to oven. Bake apples until tender, about 12 minutes. Place 2 apple halves in each serving dish, cut sides up, and drizzle with butter mixture from skillet. Garnish with cinnamon sticks from skillet. Serve warm.