Preheat the oven to 350°F.
In a large bowl, mix apples, butternut squash or pumpkin, and cranberries.
Mix brown sugar, coconut oil, cornstarch, salt, nutmeg, and cinnamon and toss to evenly distribute.
Place the squash mixture in an ungreased 1 ½ to 2 quarts prepared baking dish, cover with foil and bake for 20-25 minutes.
Remove from oven and toss lightly. Bake, covered, for an additional 30-35 minutes, or until squash and apples are tender when pierced with a fork.
Let the casserole cool for about 10-15 minutes to allow the liquid in the bottom of the dish to thicken slightly. Serve warm.