Prepare a butternut squash by peeling it, removing the seeds, and cutting it into cubes. Place it in a baking dish. Add the red onion and garlic.
Toss everything with olive oil, salt, and pepper, then bake at 350°F for 40 minutes.
Place your sausages on a sheet pan lined with parchment paper and put them in the oven for the last 15 minutes of the squash's cooking time. Make sure to turn the sausages halfway through the cooking time.
Cook the pasta until it's al dente, and reserve 1/2 cup of cooking water.
Once the vegetables are ready, put them in a food processor, add the spices and a bit of cooking water. Add the ricotta and blend until you achieve a smooth consistency.
After the sausages are cooked, cut them into quarters. Optionally, you can sear them briefly in a hot pan.
In a pan or a pot, combine the pasta, sauce, and sausages. Add the cheddar cheese and mix.