Preheat oven to 200°C conventional.
Melt the butter. Add cream, sugar, spice and 1 tablespoon of rum and mix to combine well.
Place apples in a large baking tray, cut side down, and brush on butter mixture with a pastry brush. Turn apples to cut side up and brush again generously. Reserve the remaining mixture to serve. Pour some water into baking dish so that base is just covered to avoid apples burning.
Bake for 30-50 minutes depending on how ripe your apples are (allow for a longer time if they are crunchy), carefully basting with juices in bottom of pan every 10 minutes. The apples are ready when they are starting to fall apart and collapse into themselves.
Allow to cool before serving.
