Preheat oven to 350°F. Grease muffin tins, or coat with non-stick spray.
In a small bowl, pour hot water over raisins. Let sit 10 minutes; drain well and set aside.
In a medium bowl, combine flour, oatmeal, sugar, baking powder, salt, cinnamon, allspice, and nutmeg. Stir and toss to combine ingredients; set aside.
Peel and core apples, then coarsely grate; you need 2 generous cups, lightly pressed down.
In a medium bowl, combine grated apple with egg, egg whites, oil, and walnuts; beat to blend.
Add apple mixture and raisins to dry ingredients; stir until just blended and moistened. Batter will be very stiff.
Spoon into prepared muffin tins, filling the cups ¾ full.
Bake at 350°F for 20 to 25 minutes, or until a toothpick inserted in a muffin comes out clean. Cool 5 minutes in the pan, then remove and serve warm.
Source: California Walnut Board