01 - Preheat oven to 350°F (175°C). Grease a 9x9-inch baking dish to prevent sticking.
02 - In a large mixing bowl, thoroughly mix rolled oats, chopped nuts, baking powder, ground cinnamon, ground nutmeg, and salt.
03 - In a separate bowl, whisk together milk, eggs, melted butter, maple syrup, and vanilla extract until well combined.
04 - Pour wet mixture into dry ingredients and stir until evenly mixed. Gently fold in diced apples and dried fruit.
05 - Transfer mixture to the prepared baking dish, spreading it into an even layer.
06 - Bake in the preheated oven for 35 minutes or until the top is golden brown and the oatmeal is set in the center.
07 - Let cool for 5 minutes before cutting and serving. Optionally, serve with additional milk or a dollop of yogurt.