Cream butter, sugar, vanilla, rum. Add eggs one at a time. Add dry ingredients. Add buttermilk. Bake @350 in greased mini cake pans for 25-30 min. When cakes are done, poke holes with wooden skewer or toothpick.
Sauce:
While cakes bake, heat sauce ingredients over med until combined and beginning to boil. Remove from heat and pour over cakes.