Here's a great recipe made from naturally sweet Ontario Eating Apples such as Empire, McIntosh, Golden Delicious Idared or others.
30 to 40 minutes
In a bowl, combine oats, flour, 1/3 cup (75 mL) of the brown sugar, half the cinnamon and the salt. Stir in half the apple juice and all the butter. Set aside.
In a greased 8-inch (2 L) square baking dish, combine apples, lemon juice, remaining apple juice, remaining brown sugar and remaining cinnamon. Sprinkle oatmeal mixture evenly over apples. Bake in a 375°F (190°C) oven until apples are tender and topping is golden brown, 30 to 40 minutes.