This Can’t be Squash Casserole
No one will be able to tell that the main ingredient in the squash casserole is squash because it is so rich and delicious with lots of Cheddar cheese, creamy mushroom soup, and mayonnaise.
Set oven to 350 degrees Fahrenheit (175 degrees C).
A 9×13-inch casserole dish should be sprayed with cooking oil.
Cook squash in a large pot of boiling, salted water for 10 to 15 minutes, or until very tender.
Squash should be drained, then moved to a large bowl and mashed until completely smooth.
In a skillet over medium heat, melt the butter.
Cook and stir the onion for 5 to 10 minutes, or until it is tender.
Combine onion and mushroom soup.
When making mashed squash, add cheddar cheese, bread crumbs, milk, mayonnaise, sugar, salt, and pepper.
Fill the casserole dish with the mixture evenly.
Bake for 45 to 1 hour in a preheated oven, or until bubbling and the edges are lightly browned.