While waiting for pasta to cook, cook crumbled Italian sausage in large skillet, about 7 to 8 minutes. (If sausage is in casings, remove and cook.) After sausage is browned add onions and saute, about 8 to 10 minutes, until golden. Add garlic, salt and pepper and saute for 30 seconds.
Drain the cooked pasta and combine with sausage mixture. Add extra-virgin olive oil and fresh basil and toss gently to combine.