Preheat the oven to 350F. Peel pears and carefully remove the core using a melon baller or a tiny teaspoon. If necessary, slice a little off the bottom so they will stand upright. Arrange in a deep baking dish with a lid.
Mix the orange juice concentrate with water. Drizzle it and the liqueur over the top of the pears, sprinkle with the sugar and ground spices and add the broken cinnamon sticks, whole cloves, allspice and star anise.
Cover and bake for 45 minutes, basting every 15 minutes, until pears are tender when pricked with a fork. Remove the lid and bake for an additional 15 minutes to reduce and thicken the sauce.
Meanwhile, mix together the mascarpone cheese and maple syrup and add finely grated orange zest.
Arrange pears in serving dishes, drizzle with sauce, top with the mascarpone and garnish with a little more orange zest.