Put half the milk into a saucepan over low heat. Whisk in the cornmeal and bring to a boil. Reduce the heat to a simmer, stir, and cook the cornmeal for 15 minutes over a very low flame. Stir frequently to keep smooth.
Combine the syrup, molasses, rum and spices in a small bowl to ensure even distribution of flavorings throughout the pudding.
Stir the butter into the cornmeal, add the remaining ingredients, trying to combine as uniformly as possible. Pour the pudding into a buttered 3 quart baking dish, pour the remainder of the cold milk on top of the pudding and bake for 1 1/2 hours. Allow to cool and it will set up and tighten.