Mix and place in 9x13:
10 cups sliced apples
3/4 cup sugar (depending on the apple you use; 1 cup for Granny Smith, 1/2 cup for Honey Crisp)
3 T flour
1/2 cup water
1 tsp cinnamon

Combine:
1 cup quick oatmeal
1 cup flour
1 cup brown sugar
1 stick melted butter
1/2 t soda
1/2 t baking powder
1/2 cup chopped nuts
Spread over apples and bake 325 degrees for 45 minutes.