To prepare a squash casserole with cream of chicken soup recipe, you will first need to prepare the squash. Squash can be purchased at most grocery stores, or you can make it at home. You will need: 1 1/2 cups butternut squash, 1 cup shredded cheddar cheese, 2 tablespoons mayonnaise, 1/2 teaspoon kosher salt, 1/4 teaspoon ground black pepper, and 1 teaspoon cayenne pepper. Preheat the oven to 375 degrees F (190 degrees C) and prepare your oven rack to line the bottom and top of the dish with foil. Cut your squash in half lengthwise and scoop out the seeds. Place the flesh side down on the foil-lined dish. Bake for 30 minutes or until squash is heated through and cheese is melted. Serve warm.