Prepare the Apples: Slice about 3 large apples and combine them in a bowl with the sugar, cornstarch, cinnamon, and lemon juice.
Transfer the apple mixture to an oven-safe 9-inch cast-iron skillet (or similar-sized oven-safe baking dish).
Make the Topping: In a separate bowl, stir together the quick oats, flour, brown sugar, and nutmeg. Pour in the melted butter and mix until crumbly.
Assemble and Bake: Sprinkle the oat topping evenly over the apples in the skillet.
Bake for 35 to 45 minutes, or until the topping is golden brown and the apples are bubbly
Notes
This recipe is so easy to make, and can be adjusted to anyones liking. Sometimes I will add in some other berries to give it a mixed berry flavor, or even add a scoop of ice cream on top. Recipes like this are so easily adaptable!