This has been a family favorite for many years, and is very good. To make a bigger dish for a crowd, I increase some of the ingredients (see below).
Squash Casserole
1 Cup Water
2 Teaspoons Salt, Divided
1/8 Teaspoon Sugar
6 Medium Yellow Squash, Sliced
1 Stick of Butter (room temperature, divided)
1 Cup Shredded Cheddar Cheese
1 Carton Sour Cream (8 OZ.)
4 - 5 green Onions, chopped
1/2 Cup Grated Parmesan Cheese
1 Cup Bread Crumbs
Preheat oven to 350 degrees. Add 1 teaspoon salt and 1/8 tsp. sugar to water and simmer squash over low heat, covered, until not quite tender (they will cook more in the oven). Drain squash and return to pan. Add 4 tablespoons butter and blend with squash. Stir in cheddar cheese, sour cream and green onions, 1 teaspoon salt, and parmesan cheese. Pour squash mixture into greased casserole dish. Top with bread crumbs and dot with remaining butter. Bake 30 minutes.
NOTE: I use about 10 medium squash, 6 green onions and a little more cheddar cheese, parmesan cheese, and sour cream to make a casserole for a 9x13 dish. This is also good when you mix Yellow and Zucchini squash.