Can’t get much more classic than this.
From the box of Evia Marie Sands of Louisville, Kentucky.
1/2 cup flour
1/2 cup rolled oats
1 cup brown sugar
1/3 cup butter
Cinnamon and nutmeg [to taste]
Cover pan with sliced apples (a layer of apples approximately 1/2 inch thick). Mix above ingredients together and pour over apples. Bake in oven for approximately 1/2 hour.