How to Make It
Preheat the oven to 350°. Set the squash on a large rimmed baking sheet, cut sides up, and brush with the 3 tablespoons of melted butter. Sprinkle the sugar in the cavities and season the squash with salt and pepper. Turn the squash over on the baking sheet and roast for about 1 hour, or until tender and browned at the edges.
Meanwhile, heat the remaining 2 tablespoons of butter in a medium skillet. Add the chestnuts and thyme sprigs and cook over moderate heat, stirring occasionally, until the chestnuts are lightly browned and glazed with the butter, 8 to 10 minutes. Discard the thyme sprigs.
Cut each squash half into 4 wedges and arrange on a large platter. Sprinkle with the glazed chestnuts and the red currants. Drizzle the squash with the pomegranate molasses and serve.
Sweet-tart pomegranate molasses is available at specialty-food shops and Middle Eastern markets.