Spray 8 x 11-inch baking dish with cooking spray and set aside.
Pour boiling water over oatmeal in a bowl. Let sit for 5 minutes. Add other ingredients. Mix and pour into prepared pan.
Cover with foil and bake at 350-degrees for 40 minutes. Remove foil and continue baking for another 10 minutes.
When preparing baked oatmeal for the week ahead, be sure to cool completely before refrigerating. Cover the baking dish with foil or plastic wrap or store individual servings in individual glass serving dishes for easy reheating. Refrigerate for up to one week. Enjoy!
This recipe can be served right away, or it can be chilled and stored. Our family loves the leftovers. Serve with a sprinkle of fresh blueberries and brown sugar, heavy cream, half-n-half, milk, or nut milk.