Place pecans on a baking sheet, and bake at 350° for 12 to 15 minutes or until golden brown, stirring once. Set pecans aside.
Make 4 evenly spaced vertical cuts through each apple, stopping halfway from bottom. Brush insides of apples with lemon juice. Place apples in a 9-inch pie plate.
Combine 1 tablespoon butter, raisins, and next 4 ingredients. Stuff mixture evenly into apples, pressing into center of each apple. Top evenly with remaining 1 tablespoon butter. Pour cider, vanilla, and, if desired, rum around apples in pieplate.
Bake at 350° for 1 hour and 20 minutes, basting twice every 30 minutes or until apples are tender. Transfer apples to a serving dish, reserving juices, and keep warm.
Pour juices through a wire-mesh strainer into a small saucepan. Bring to a boil; reduce heat and simmer over medium heat 8 to 10 minutes or until mixture is thickened and is syrup consistency. Drizzle over warm apples; garnish, if desired. Serve immediately.