Preheat the oven to 400°. Using a grapefruit knife or a sharp paring knife, cut a ring around each pumpkin stem to form a lid; remove the lids and set aside. With a small spoon, scrape out the seeds and any membranes.
In a small bowl, combine the cinnamon, nutmeg, and allspice and sprinkle the spices inside the pumpkins. Add 1/2 tablespoon of the butter and 1 teaspoon of the maple syrup to each pumpkin and season with salt and pepper.
Set the pumpkins in a baking dish and add 1/2 inch of water. Replace the lids and roast the pumpkins for about 30 minutes, or until tender. Serve hot.