1. Lightly grease a 9" x 13" pan. Set aside.
2. In a large bowl combine the rum and raisins. Cover with plastic wrap, and microwave until just warm, about 30 seconds. Set aside.
3. In the bowl of an electric mixer fitted with a dough hook add in all of the bun ingredients, exceptt for the raisins. Knead the mixture, until the dough is soft and elastic, about 6-8 minutes. Add in the raisins and all residual liquid. Mix for an additional minute to distribute the raisins.
4. Let the dough rise in a warm location for 1 hour, covered. It should become puffy, though may not double in bulk.
5. Divide the dough into 1/3 cup or 3 3/4 ounce portions, you should have 12-14 rolls. Roll the dough into smooth balls and arrange in prepared pan. Arrange them in the prepared pan, cover and let the buns rise for 1 hour or until they are touching.
6. Preheat oven to 375º F.
7. Whisk together the reserved egg white and the milk, brush the buns.
8. Bake for 20-25 minutes or until buns are golden brown. Turn buns out of the baking pan onto a cooling rack. Cool completely.
9. In a bowl combine the icing ingredients. Decorate each bun with a cross shape on top.