Preheat oven to 300°F.
Cover a large rimmed cookie sheet with heavy duty foil and spray well with coconut oil spray. Set aside.
In a coffee grinder, grind about 1/4 c of mulling spices if whole into a fine powder. (See note for other options.)
In a medium to large bowl, combine the dry ingredients, oats through the mulling spices (it's a skimpy 1/4 c). Stir well.
Mix in the almond milk and egg whites. Mixture will seem very dry, but keep stirring and the dampness will cover the oats. This is not a wet mix.
Add the walnut pieces and stir again.
Spread across the foil-lined cookie sheet, and bake for 50 min, stirring halfway through.
After 50 min, stir in the dehydrated apple pieces, and bake for ten more minutes.
Remove from oven and enjoy! (I like mine topped with additional original unsweetened almond milk, but it's good by itself, too!)