1. Place potatoes on an aluminum foil-lined baking sheet. Bake at 425° for 1 hour and 15 minutes or until tender.
2. Heat nuts in a nonstick skillet over medium-low heat, stirring often, 5 to 7 minutes or until toasted. Remove from skillet.
3. Melt butter in skillet over medium-high heat. Add apple and raisins; sauté 2 to 3 minutes or until apple is tender. Stir in brown sugar, cinnamon, and nutmeg. Remove from heat.
4. Cut potatoes in half lengthwise; scoop pulp into a large bowl, leaving shells intact. Add apple mixture to pulp in bowl; stir until blended. Spoon mixture into shells. Place on baking sheet.
5. Bake at 350° for 15 to 20 minutes or until thoroughly heated. Top with nuts.