Squash casserole is a classic Southern side dish filled with yellow squash and creamy cheeses. It can be served as a rich side dish or a filling vegetarian main. The buttery cracker topping really makes this dish stand out!
Preheat oven to 350 degrees. Lightly grease a 9x9 baking pan or casserole dish.
Heat canola oil in a large skillet over medium high heat. Add in squash and onion and season with salt. Cooking, stirring frequently until squash just starts to soften and liquids have been released, about 7 to 10 minutes. Drain well.
In a large mixing bowl stir together sour cream, cheddar cheese, parmesan, and egg until well combined. Add in squash and gently fold until well coated. Pour into the prepared baking pan.
In another small bowl, toss together crushed crackers, butter, and parmesan cheese. Sprinkle over the top of the squash.
Bake at 350 degrees for 20 to 25 minutes, uncovered, until topping is lightly browned. Serve hot.