Preheat oven to 350.
In a large bowl, combine frozen peaches, 1/4 cup xylitol, and 1/2 teaspoon cinnamon. Toss to coat.
Pour peaches into a greased 12 inch cast iron skillet.
In another bowl, mix all remaining ingredients.
Pour oatmeal mixture over peaches.
Bake for 50-55 minutes, or until center is set and no longer jiggles.