01 - Preheat oven to 350°F (175°C) and grease a 9x9-inch baking dish thoroughly.
02 - In a large mixing bowl, blend together rolled oats, chopped nuts if using, baking powder, ground cinnamon, ground nutmeg, and salt until evenly distributed.
03 - In a separate bowl, whisk milk, eggs, melted unsalted butter, maple syrup, and vanilla extract until smooth.
04 - Pour the wet mixture into the dry ingredients and stir until fully combined. Gently fold in diced apples and optional dried fruit.
05 - Spread the oat mixture evenly into the prepared baking dish, ensuring an even surface.
06 - Bake in the center of the oven for 35 minutes, or until the top is golden brown and the bake is set in the middle.
07 - Allow to cool for at least 5 minutes before serving. Serve warm with additional milk or a spoonful of yogurt, if desired.