Preheat the oven to 425°F (220°C).
Bring a large pot of salted water to a boil. Cook the tortellini according to package instructions until just al dente, usually about 2-3 minutes for refrigerated or frozen tortellini. Drain and set aside.
In a large bowl, combine the Italian sausage and break it into small pieces with your hands or a spoon.
Add the sliced red and yellow bell peppers, zucchini rounds, and cherry tomato halves to the bowl with the sausage.
Drizzle the olive oil over the sausage and vegetables. Sprinkle the Italian seasoning, garlic powder, salt, and black pepper on top.
Toss everything together until the sausage and vegetables are evenly coated with oil and seasonings.
Spread the sausage and vegetable mixture evenly on a large rimmed sheet pan.
Roast in the preheated oven for 15 minutes.
Remove the sheet pan from the oven and gently add the cooked tortellini to the pan, mixing carefully to combine with the sausage and vegetables.
Return the sheet pan to the oven and roast for an additional 10 minutes, or until the sausage is fully cooked and the vegetables are tender.
Remove from the oven and sprinkle grated Parmesan cheese and chopped fresh basil over the top.
Serve warm directly from the sheet pan.