Preheat oven to 350 degrees F.
Wash and thinly slice apples lengthwise (keep the skin on for extra fiber!)
Add to a large mixing bowl and top with remaining filling ingredients. Toss to combine.
Add apple and pumpkin mixture to a 9x13 baking dish.
In another small bowl add all topping ingredients. Stir to combine, then use fingers to break down any clumps of sugar. Pour over apples in an even layer.
Bake for 45-50 minutes (uncovered) or until the filling is bubbly, and the apples are very fork tender.
Top with extra gluten free granola if desired and serve with ice cream or pumpkin spice greek yogurt.
Keep the leftovers covered in the refrigerator up to 3 days. Reheat in the microwave.