01 - Preheat oven to 350°F. Lightly grease a 9x9-inch baking dish with butter or cooking spray.
02 - In a large bowl, combine rolled oats, nuts, baking powder, ground cinnamon, ground nutmeg, and salt.
03 - In a separate bowl, whisk together milk, eggs, melted butter or coconut oil, maple syrup or honey, and vanilla extract until well blended.
04 - Add the wet mixture to the dry ingredients and mix until incorporated. Gently fold in diced apples and raisins or dried cranberries.
05 - Pour the combined mixture into the prepared baking dish. Spread evenly with a spatula.
06 - Place in the oven and bake for 35 minutes, or until the surface is golden brown and set.
07 - Remove from oven and allow to cool for 5 minutes before slicing. Serve warm with extra milk or yogurt if desired.