This is not for the calorie conscious, but it is soooo good.
- Preheat oven to 350. Grease a 2-quart casserole.
- Heat the oil in a large skillet over medium heat. Sauté the squash, onion, and butter until soft. Transfer to a bowl and stir in the Parmesan, Cheddar, and sour cream. Add salt and pepper, to taste.
- Place in the prepared casserole dish and sprinkle the cracker crumbs evenly over the top. Bake for 20 minutes or until the top is golden and bubbly.