Preheat oven to 350 degrees F. Spray a baking dish with cooking spray and set aside.
In a large bowl, combine all the ingredients for the apple base. Mix well.
Pour the apple mixture into the baking dish.
In a separate bowl, mix all ingredients except for butter.
Once ingredients are well-combined, add cold butter and use a pastry cutter to combine. Once the mixture feels like slightly wet sand, it’s ready.
Spread the crumble topping on top of the apple mixture. Bake for about 45 minutes.
Serve warm with a side (or a topping!) of vanilla ice cream. Enjoy!