Preheat your oven to 375 degrees.
Spray a 8x8 glass 8x8 dish with cooking spray.
Peel and core your apples. Cut them into thin slices. Place them on the bottom of your glass dish, spreading evenly.
Make your sauce by combining 1/2 cup packed brown sugar, 1/2 tsp. cinnamon, and 1/4 cup water. Pour sauce over apples.
Now you make your crumble. Mix 1/2 tsp. cinnamon, 1/2 cup flour, 1/2 cup oats, 1/2 cup packed brown sugar, and 1/2 cup softened butter (do not melt). Use a pastry blender or a fork to mix until crumbly. Sprinkle over the top of the apple mixture.
Sprinkle a little cinnamon over the top and bake at 375 degrees for 30-40 minutes, until the apples are tender.
Let cool for 10 minutes and serve with ice cream or whipped cream. You can also drizzle caramel ice cream syrup topping over the top.