Creating Apple Cinnamon Baked Oatmeal is straightforward with these easy steps:

1. Preheat Oven: Start by preheating your oven to 350°F (175°C). Grease a 9×13 inch baking dish.
2. Mix Dry Ingredients: In a large bowl, combine the rolled oats, baking powder, ground cinnamon, nutmeg, and salt. Mix well.
3. Combine Wet Ingredients: In another bowl, whisk together the milk, eggs, maple syrup, and vanilla extract until well blended.
4. Fold in Apples: Add the diced apples and optional nuts to the bowl with the wet ingredients and stir until just combined.
5. Combine Mixtures: Pour the wet ingredients into the dry ingredients. Stir until all oats are coated and moist.
6. Transfer to Baking Dish: Pour the combined mixture into the prepared baking dish and spread it evenly.
7. Sprinkle Topping: If desired, sprinkle a little extra cinnamon on top for added flavor.
8. Bake: Place the baking dish in the preheated oven and bake for 35-40 minutes or until the top is golden and the mixture is set.
9. Cool and Serve: Remove from the oven and allow to cool for about 5-10 minutes before serving.

These steps will guide you in effortlessly creating this delicious and nutritious breakfast.