For Topping:
In a med. sized bowl add brown sugar, cinnamon, nutmeg, salt, flour, oats, and butter.
Cut butter into ingredients until mixture is crumbly but still comes together if pressed. Set aside.
For Filling:
Peel and cut apples into thin slices. Set aside.
In a large bowl combine brown sugar, flour, cinnamon, nutmeg, salt, lemon juice, and melted butter.
Mix until its all combined.
Drain water from apples and evenly coat the apples in the mixture.
Preheat oven to 350 Degrees
Grease the bottom of a 9x9 baking pan
Pour apples and the filling mixture into greased pan
Sprinkle the topping over top
Bake for 40 minutes or until apples are tender