Preheat the oven to 375 degrees F.

Bring a pot of salted water to a boil and boil the pasta according to the directions. When it’s finished, drain and place the pasta in a 9x13 inch baking dish.

While the pasta is boiling, brown the sausage. Heat a large skillet over medium heat and add the sausage. Break it apart with a wooden spoon until it is in small crumbles and browns completely. Transfer the sausage to a plate.

To the same skillet, heat the olive oil over medium-low heat. Add the onions, garlic, squash and a big pinch of salt and pepper. Add in the sage and crushed red pepper. Cook, stirring often, until the squash is tender, about 8 to 10 minutes.

Once the squash is tender, stir in the spinach. Cook until the spinach wilts. Transfer that whole mixture - the squash and spinach - to the dish with the pasta. Add the sausage back in. Toss it with the pasta until it’s fully combined.

Stir in half of the cheese until it’s mixed in with the pasta. Stir in the parmesan. Top the pasta with the rest of the cheese.

Bake for 20 to 25 minutes, or until bubbly and golden.

Remove and sprinkle with more parmesan before serving.