- Preheat your oven to 350°F (175°C) and grease a 9x9-inch baking dish. 
- In a large mixing bowl, combine the rolled oats, milk, diced apple, brown sugar, cinnamon, vanilla extract, and salt. Stir until well mixed. 
- In a separate bowl, beat the eggs and then add them to the oat mixture. Stir until fully incorporated. 
- If using, fold in the chopped nuts and dried fruit. 
- Pour the mixture into the prepared baking dish, spreading it evenly. 
- Bake in the preheated oven for 30-35 minutes, or until the top is golden brown and the oatmeal is set. 
- Allow to cool for 5-10 minutes before slicing and serving.