In medium bowl stir together flour, baking powder, cinnamon, salt and nutmeg. Set aside.
In large bowl combine KELLOGG'S COMPLETE Wheat Flakes cereal, milk and sugar. Let stand 2 minutes or until cereal softens. Add egg whites and oil; beat well.
Add flour mixture to cereal mixture, stirring just until combined. Evenly portion batter into twelve 2 1/2-inch muffin-pan cups coated with cooking spray or lined with foil bake cups.
Bake at 375° F about 15 minutes or until toothpick inserted in center comes out clean. Let cool in muffin pan for 5 minutes. Transfer to wire rack. Cool completely.