Preheat your oven to 350 degrees Fahrenheit (175 degrees Celsius), and spray a 9x9 inch baking dish with baking spray.
Chop the apples into small pieces (about 3/4-inch pieces) and add them to a mixing bowl.
Add the brown sugar and spices and toss everything together very well until combined. Set it aside.
In a separate bowl, combine the sugar, cinnamon, oats, flour, and salt for the topping.
Cut the cold butter into small pieces and add them to the bowl with the topping ingredients. Use your hands or a pastry cutter to crumble the butter into the dry ingredients until the mixture resembles coarse crumbs.
Add the apples to the baking dish and even out the top.
Add the topping on top of the apples, making sure the top is even.
Bake at 350 degrees Fahrenheit (175 degrees Celsius) for 35-40 minutes until the top is brown and crispy.
Serve hot with vanilla ice cream, whipped cream, or on its own.