1. Preheat your oven to 400°F (200°C).
2. Place the halved acorn squash cut-side up on a baking sheet.
3. In a small bowl, combine the butter, maple syrup (or honey), and chopped rosemary. Mix well until thoroughly combined.
4. Spoon the buttery syrup mixture evenly into the scooped-out centers of each squash half, making sure to coat the flesh well.
5. Bake in the preheated oven for about 40-50 minutes, or until the squash is tender and easily pierced with a fork. Remember to baste the insides of the squash with the melted mixture from the center occasionally throughout the baking process for extra flavor.
6. Once done, remove from the oven and sprinkle the toasted pecans over the top. Serve warm, and enjoy it by scooping out the flavorful flesh with a spoon!