Annie's Squash Casserole

Ingredients:
2 C of cooked squash
¼ C (= ½ of a stick) of butter
¼ - ½ C of chopped onion
1 C of grated sharp cheddar cheese
1 egg
½ C of milk
Salt and pepper

Directions:
Spray casserole dish with PAM. Mix all of the above ingredients and pour into dish.
Topping:
½ C (= 1 stick) of butter
1 C of Ritz Cracker crumbs (I mixed ½ C of Ritz and ½ C of Cheese-Its crackers)
Sprinkle over casserole and bake at 350 degrees for 30 minutes.