Preheat the oven to 350 degrees . In a small bowl, combine the raisins and rum; let stand for 10 minutes. Drain, reserving the liquid.
Spread the cornbread evenly on a baking sheet and toast in the oven for 10 minutes. Remove from the oven; lower the temperature to 325 degrees .
In a large bowl, whisk together the eggs, coconut milk, evaporated milk, butter, reserved soaking liquid, sugar and salt. Stir in the raisins, fold in the cornbread and let stand for 10 minutes.
Transfer the cornbread mixture to a greased 8-inch square baking dish and bake until crusty and golden, about 50 minutes.