To ensure the apples don't split open as they bake, make a shallow horizontal cut around the middle of each one.Plus: More Dessert Recipes and Tips
Preheat the oven to 400°. Set the apples in a small baking dish so they don't touch one another.
In a small bowl, mix together the sugar, walnuts, raisins, cardamom, nutmeg and cinnamon. Spoon the mixture into the apples and top each with 1/2 teaspoon of butter. Loosely cover the apples with foil and bake for about 45 minutes, or until the apples are just tender when pierced. Serve warm or at room temperature, with heavy cream if desired.