Preheat oven to 350 degrees F. Lightly coat a 9 x 13 inch baking dish with cooking spray or line with parchment paper.
In a medium bowl, stir together oats, baking powder, salt, cinnamon, and nutmeg.
In another medium bowl, whisk together milk, applesauce, maple syrup, vanilla, chopped apples, and raisins (if desired). Stir the oat mixture into the wet ingredients.
Sprinkle the top with pecans and brown sugar
Bake for 30 minutes or until golden brown and crunchy on top.