Preheat the oven to 190°C (375°F/Gas 5). Lightly butter a large shallow baking dish. Peel the pears and cut in half lengthways, then carefully remove the cores. Arrange in the buttered dish, cut side down in a single layer.
Place the cream in a bowl with the sugar, vanilla, cinnamon, nutmeg and root ginger, then mix until well combined. Pour over the pears and then bake for 20 minutes until the pears are almost tender and the cream mixture is well reduced.
Remove the pears form the oven and sprinkle the crumbled gingerbread on top. Bake for another 5 minutes until well heated through. The pears should now be completely tender and the cream thick and bubbly. Leave to cool slightly before serving straight to the table.