1. Preheat the oven to 350 degrees Fahrenheit. Grease a 9 x 13 x 2-inch ovenproof baking dish. In a small bowl, combine the raisins and rum and set aside.

2. Remove the crusts from the bread. In a blender or food processor, blend the crusts into bread crumbs. Set aside 3 tablespoons and reserve the rest for another use. Cube the bread and put the pieces into a large bowl. Pour the milk and coconut milk over the bread. Set aside to saturate completely.

3. In a separate bowl, beat together the eggs, sugar, vanilla, cinnamon, and nutmeg. Pour it over the bread along with the raisins and rum. Stir the mixture until well blended. Pour it into the baking dish and sprinkle the 3 tablespoons of bread crumbs over the top. Bake for 40 minutes.

4. Meanwhile, prepare the sauce. In a small saucepan, combine the brown sugar, water, butter, and rum. Bring to a boil over medium-high heat and boil gently until thickened, about 10 minutes. Pour a little over each portion when serving.