Wash, peel and slice apples. Then sprinkle 1 tablespoon of flour and 1/2 teaspoon of cinnamon over apples. Stir until well coated.
I use Fuji apples but you can use other kinds that you like. You can also mix different kinds of apples such as 2 of Granny Smith and 2 Fuji apples.
Spread sliced apples in pan
Combine flour, oats, sugar and 1/2 teaspoon of cinnamon.
Add cold butter that are cut into small cubes.
Use forks or hand to mash butter into the mixture.
Mix until the mixture resembles coarse crumbs.
Spread the oats mixture over apples and pat gently.
Bake in oven for about 40 minutes or until the topping turns golden brown.