Preheat your oven to 375°F.

Bring a large pot of salted water to a boil. Add the pasta and cook until just al dente (about 1-2 minutes less than the package directions). Drain the pasta and set aside.

In a large skillet over medium heat, warm 3 tablespoons of olive oil along with 2 tablespoons of the unsalted butter. Season the shrimp with salt and pepper, then add them to the skillet. Cook for 1-2 minutes per side until they turn pink and are just cooked through. Remove the shrimp and set aside.

Using the same skillet, add the remaining 2 tablespoons of butter. Sauté the minced garlic and crushed red pepper flakes (if using) for about 30 seconds until fragrant.

Pour in the chicken broth, lemon juice, and lemon zest. Stir to combine and allow the flavors to meld for a minute.

In a baking dish, combine the drained pasta, cooked shrimp, and the garlic-lemon sauce from the skillet. Sprinkle the grated Parmesan cheese evenly over the mixture, then top with shredded mozzarella cheese.

Bake in the preheated oven for 15-20 minutes, or until the cheese is melted, bubbly, and has a beautiful golden hue.

Remove from the oven and garnish with fresh chopped parsley before serving.