Preheat the oven to 425°F (220°C).
Line a large sheet pan with parchment paper or lightly grease it with cooking spray.
In a large bowl, combine the broccoli florets, olive oil, garlic powder, Italian seasoning, salt, black pepper, and red pepper flakes. Toss until the broccoli is evenly coated.
Spread the broccoli mixture evenly on one side of the prepared sheet pan.
Add the Italian sausage to the other side of the sheet pan, breaking it into small chunks.
Place the sheet pan in the preheated oven and roast for 10 minutes.
While the sausage and broccoli roast, bring a large pot of salted water to a boil.
Add the tortellini to the boiling water and cook according to package instructions, usually 3 to 5 minutes, until they float to the surface.
Drain the tortellini and set aside.
After the initial 10 minutes of roasting, remove the sheet pan from the oven and stir the sausage and broccoli to ensure even cooking.
Add the cooked tortellini to the sheet pan, distributing it evenly among the sausage and broccoli.
Sprinkle the shredded Parmesan cheese evenly over the entire sheet pan.
Return the sheet pan to the oven and roast for an additional 10 to 15 minutes, until the sausage is fully cooked, the broccoli is tender and slightly charred, and the cheese is melted and golden.
Remove from the oven and let cool for 2 minutes before serving.