First, preheat the oven to 375ºF and spray a 9x9-inch baking dish with nonstick cooking spray. You can also use a bigger casserole dish such as a 9x13-inch. Either will work.

Then, prep apples by peeling and dicing into small pieces. Then transfer them to the bottom of the casserole dish and pour in orange juice and sprinkle on four. Toss and set the mixture aside.

In a separate large bowl, mix together crumble topping. Place rolled oats, white whole wheat flour, brown sugar, cinnamon, and salt.

Then, add in a stick of softened butter and use a fork (or your hands) to cut the butter into the dry ingredients until it forms little crumbles.

Evenly spread crumble topping over the apples in the casserole dish.

Bake at 375ºF for 40 minutes or until the apple filling begins to bubble, the apples are at the desired consistency, and the crumble topping begins to brown.

Serve with fresh whipped cream or a scoop of vanilla ice cream.