This crumb-topped butternut squash casserole is made with a combination of sliced butternut squash and apples. The apples complement the squash perfectly and the simple crumble toppinglightly spiced with cinnamon and nutmegis the perfect finishing touch. This is an excellent side dish for any fall meal and it would be a perfect holiday dinner casserole. Pecans would be good in the topping as well or use chopped walnuts. It's a good lower carb alternative to a crumb-topped sweet potato casserole, too. Or add it to your menu along with a sweet potato dish. You can make this casserole with other types of winter squash as well. Hubbard squash, acorn squash, and sugar pumpkins can be used as a replacement for butternut squash in any recipe.