Preheat oven to 375 degree F. In a small bowl combine the walnuts, raisins, brown sugar, cardamom, and nutmeg; set aside.
Slice off a thin slice from the bottom of apples to allow them to stand flat. Core apples, starting from the stem end, using a melon baller or small spoon, going to but not through the bottom of the apple. Place apples in a 2-quart square baking dish. Stuff apple cores with fruit and nut mixture, mounding filling as necessary. Place 1 teaspoon butter on top of filling of each apple.
Pour cider and honey into the bottom of the baking dish. Loosely cover apples with foil.
Bake for 25 minutes. Remove foil; bake, uncovered, for 20 minutes more or until apples are tender, spooning liquid over apples occasionally.
Cool slightly. Serve warm topped with yogurt and drizzled with cooking liquid. Makes 4 servings.