01 - Preheat oven to 350°F. Grease a 9x9-inch baking dish with butter or non-stick spray.
02 - In a large mixing bowl, combine rolled oats, chopped nuts, baking powder, ground cinnamon, ground nutmeg, and salt until evenly mixed.
03 - In a separate bowl, whisk together milk, eggs, melted unsalted butter, maple syrup, and vanilla extract until smooth.
04 - Add wet ingredients to the dry ingredients. Stir gently until fully combined. Fold in diced apples and dried fruit, distributing evenly.
05 - Pour the oatmeal mixture into the prepared dish and spread into an even layer.
06 - Bake for 35 minutes, or until the top is golden brown and the center is set.
07 - Allow to cool for 5 minutes before portioning. Serve warm, optionally with a splash of milk or a dollop of yogurt.