Not specified

1. Preheat oven to 350°.
2. Spray an 8x8-inch (20x20cm) baking dish lightly with cooking spray.
3. In a small mixing bowl, whisk together the sour cream and eggs.
4. In a large skillet or medium Dutch oven over medium heat, melt the butter.
5. Add the onions, and cook stirring occasionally, until the onions begin to soften and brown on the edges, about 4 to 5 minutes.
6. Add the squash, thyme, salt, and pepper.
7. Cook, stirring occasionally until squash is tender and onions are very soft, about 7 to 10 minutes more.
8. Remove the skillet from the heat and stir in the sour cream mixture, 2 cups (480ml) cheddar cheese, and Parmesan until well incorporated and the cheeses are mostly melted.
9. Transfer the mixture to the prepared baking dish and sprinkle with the remaining cup of cheddar cheese and crushed butter crackers.
10. Bake for 45 minutes or until the mixture is bubbling and the crackers are golden brown.
11. Let the casserole rest for 15 to 20 minutes before serving.

Not specified