Wash apples. With an apple corer, carefully pierce and cut out the stem, crown and core of each apple. Do not peel the apples, and leave the bottom intact. . Place them in an ovenproof dish.
Prep the filling: Sprinkle raisins with the rum. Add walnuts and sugar. Mix well.
Fill the apples with the raisin mixture. Pour the wine around the apples in the dish; dot the apples with little pieces of the butter. Cover with aluminum foil. Bake at 420 for about 30 minutes. (Time depends on type of apple.).