1. Soak raisins in rum for 2-3 hours or overnight to soften them; drain.
2. Preheat oven to 350°; place 18 paper baking cups in muffin pans.
3. In a large bowl, combine all the cupcake ingredients (butter through eggs) and beat with an electric mixer until smooth and pale, about 2-3 minutes.
4. Stir in raisins; spoon batter into cups; bake for about 20 minutes.
5. While the cupcakes are in the oven, combine the syrup ingredients in a saucepan; over low heat, dissolve the sugar in the rum.
6. Simmer 5 minutes, then remove from heat.
7. Remove pan from oven; with a toothpick, prick 5 holes in each cupcake and pour the warm syrup over them.
8. Then remove the cupcakes and cool on a rack.