Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the rolled oats, whole wheat flour, cinnamon, nutmeg, salt, and baking soda.
In another bowl, whisk together the applesauce, maple syrup, and chopped apples until well blended.
Gradually add the wet mixture to the dry ingredients, stirring until just combined.
Fold in raisins or walnuts if desired.
Scoop tablespoon-sized portions of dough onto a lined baking sheet.
Bake in the preheated oven for 12–15 minutes or until golden brown.
Allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack.