Preheat the oven to 375 degrees F.
Wash hands with soap and water.
Spray an 8x8 inch baking dish with non-stick cooking spray.
In a bowl, thoroughly combine the oatmeal, flour, brown sugar, cinnamon, nutmeg, and butter.
Gently rub apples under cool running water.
Core and thinly slice the apples.
Spread the apple slices evenly over the surface of the baking pan.
Sprinkle the oatmeal-flour mixture over the apples.
Bake in the preheated oven for 30 minutes or until the apples are tender and the topping is golden brown.
*For best results use a baking variety of apple like McIntosh, Granny Smith, Jonagold, or Braeburn