Spaghetti Squash Casserole with Pasta Sauce

1 . Stage

Pierce squash a few times with a very sharp knife. Place squash in a microwave-safe bowl and microwave on high power until squash is tender and a knife can easily poke through the skin, 10 to 13 minutes. Let squash rest, undisturbed, for 10 minutes.

2 . Stage

Meanwhile, preheat the oven to 350 degrees F (175 degrees C). Spray an 8-inch casserole dish with cooking spray.

3 . Stage

Heat oil in a skillet over medium heat; stir in sausage, zucchini, bell pepper, onion, and garlic. Saute, stirring occasionally, until veggies are tender and sausage is crumbly and brown, 5 to 7 minutes.

4 . Stage

Cut open squash and remove and discard all seeds. Scrape out the flesh with a fork and add to the sausage and veggie mixture. Season with salt and pepper and cook over medium heat for 5 minutes. Stir in pasta sauce and transfer to the prepared casserole dish. Top with shredded Parmesan and mozzarella cheeses.

5 . Stage

Bake in the preheated oven until heated through and cheeses are melted, about 15 minutes.