Fill a large pot with lightly salted water and bring to a rolling boil over high heat. Once the water is boiling, stir in the pasta and return to a boil. Cook the pasta uncovered, stirring occasionally, until the pasta has cooked through but is still firm to the bite, about 12 minutes. Drain well in a colander set in the sink.
At the same time, bring another large pot of lightly salted water to a boil. Stir in the broccoli rabe and cook uncovered until tender, about 6 minutes. Drain, and return to the pot along with the pasta.
Meanwhile, heat the olive oil in a large frypan over medium heat. Add the sausage and cook until firm turning frequently, about 5 minutes. Cut the sausage into 1cm pieces and sprinkle with the minced garlic, salt, onion salt, garlic powder and black pepper. Cook until the sausage is no longer pink in the centre and beginning to brown on the cut sides, about 5 minutes more. Once done, stir the sausage mixture into the pasta along with the sliced black olives to serve.