1. Preheat the oven to 375°F / 190°C. Lightly grease a large baking pan or casserole dish and set it aside.

2. Bring a large pot of salted water to a boil. Add the spaghetti or linguine and cook until al dente according to the package directions. Drain well and set aside.

3. Steam the broccoli florets for 3 to 4 minutes, or until they are bright green and tender-crisp. Set aside.

4. Melt the butter in a large skillet over medium heat. Add the minced garlic and cook for about 30 seconds, stirring constantly, until fragrant.

5. Add the shrimp to the skillet in a single layer. Cook for about 2 minutes per side, or until the shrimp turn pink and opaque. Remove the shrimp from the skillet and set aside.

6. In the same skillet, add the sliced onion and sliced red bell pepper. Sauté for 3 to 4 minutes, or until slightly softened.

7. Pour the heavy cream into the skillet and bring it to a gentle simmer. Do not boil rapidly.

8. Stir in the freshly grated Parmesan cheese, shredded mozzarella cheese, Italian seasoning, garlic powder, black pepper, and salt to taste. Stir until the cheese melts and the sauce becomes smooth and creamy.

9. Add the cooked pasta, steamed broccoli, sautéed onion and bell pepper, and cooked shrimp to the sauce. Toss gently until everything is evenly coated.

10. Transfer the pasta mixture to the prepared baking pan and spread it into an even layer.

11. Sprinkle 1 cup grated Parmesan cheese evenly over the top.

12. Bake for 15 to 20 minutes, or until the pasta bake is hot, bubbly, and lightly golden on top.

13. Remove from the oven and let it rest for 5 minutes before serving.

14. Garnish with chopped fresh parsley and serve warm.