Preheat oven to 350

Sauté the onions in the oil with the salt and pepper.

Add squash to the onions and continue to cook until the squash is tender

Drain any liquid from the cooked squash

In a bowl combine the squash mixture with the sour cream and cheddar cheese

Make your cracker crumb topping by combining the butter, the Ritz crackers and the parmesan cheese

Place your squash mixture into a greased 9x9 pan

Topping with the cracker topping

Bake for 25 minutes

If the topping gets too brown, cover the dish with foil and continue to bake until the casserole is bubbly.

Enjoy!