Preheat oven to 350F degrees and grease 9x9 baking dish with coconut oil or cooking spray.

In a large mixing bowl, combine softened butter with oatmeal. Using a pastry blender (or knife and fork), cut the butter into the rolled oats until small (pea-sized) crumbles begin to form.

Slowly add in other crust/topping ingredients, continuing to cut the mixture into crumbles.

In a medium bowl, mix together filling ingredients.

Pour half of the crust/topping crumbles into the baking dish. Using a fork, press crumbles until packed tightly into the bottom of the dish.

Spread filling evenly over crust.

Pour the remaining half of the crust/topping crumbles over the filling. Similarly to the crust, using a fork, press crumbles until tightly packed.

Bake for 30 minutes.

Allow bars to cool before cutting, but may be served warm.