Preheat your oven to 375 degrees. Line a baking sheet with foil and lightly grease with a non-stick spray. Set aside
Now prepare your butternut squash. Remove the bulbous end of the squash (you can't spiralize this end because of the seeds). Now peel the skin off the narrow end that you are going to spiralize. It's easier to cut this part in half. Spiralize the sized/shape noodles you like. Once noodles are made, drizzle with a tbsp of oil, add to the sheet pan. Salt and pepper the squash. Place in the oven and bake for 25-30 minutes.
Meanwhile, make your sauce. Heat a large skillet to medium heat. Once hot, add remaining 2 tbsp oil. Saute onion for 2-3 minutes, then add sausage. Continue to cook until sausage is cooked through about 8 minutes.
Now add garlic. Top with canned tomatoes, fresh basil, and let simmer over medium low heat for another 10 minutes stirring occasionally.
Now add coconut milk and nutritional yeast to the sauce. Continue to simmer for another 5 minutes, stirring and combining the sauce so it's nice and creamy.
Remove the noodles from the oven. Plate butternut squash noodles, pour sauce on top, and serve with fresh basil.