- Preheat oven to 350*F.
- Grease a 13x9-inch pan with nonstick cooking spray; lightly flour. Combine flour, baking soda, cinnamon, salt and nutmeg in medium bowl, set aside.
- Beat margarine with electric mixer on medium speed for 30 seconds in large mixing bowl.
- Add brown sugar and vanilla; beat until fluffy.
- Add egg whites; beat well. Add applesauce, blending well.
- Add dry ingredients and buttermilk alternately to mixture, blending well. Stir in wild rice.
- Pour into prepared pan. Bake 45 to 50 minutes or until wooden pick inserted in center comes out clean. Do not over bake.
- Cool over a wire rack. Sprinkle with powdered sugar, if desired and serve!