1. Heat oven to 350 degrees F. Lightly coat a 2-quart baking dish with nonstick cooking spray. Set aside.Filling:
2. In a large bowl, toss together sugar, flour, nutmeg and cinnamon; add cubed apples and raisins, and toss again. Let stand 10 minutes while preparing Topping: Melt butter. In medium-size bowl, stir together butter, flour, sugar, walnuts, oats, cinnamon and salt until mixture is evenly moistened and comes together in clumps.
3. Transfer apple-raisin mixture to prepared baking dish. Top with crisp topping, trying not to break up clumps.
4. Bake at 350 degrees F for 45 minutes, until bubbly and apple pieces are tender. If browning too much, cover loosely with foil during last 5 minutes of baking. Let cool 15 minutes before serving. Sprinkle with confectioners sugar.