Step 1: Preheat your oven to 375°F (190°C). Cook the pasta in a large pot of salted boiling water according to the package instructions. Drain and set aside.
Step 2: In a large saucepan, melt the butter over medium heat. Add the minced garlic and sauté until fragrant (about 1 minute). Stir in the flour and cook for 1-2 minutes until slightly golden.
Step 3: Gradually whisk in the milk and heavy cream. Bring the mixture to a gentle simmer, stirring constantly, until the sauce thickens (around 5 minutes).
Step 4: Stir in the Parmesan cheese, Italian seasoning, paprika (if using), salt, and pepper. Mix until the cheese is fully melted and the sauce is smooth.
Step 5: In a large mixing bowl, combine the cooked pasta, shredded chicken, and prepared sauce. Mix well until everything is evenly coated.
Step 6: Transfer the mixture to a greased 9x13-inch baking dish. Sprinkle the mozzarella cheese and extra Parmesan on top.
Step 7: Bake in the preheated oven for 20-25 minutes, or until the cheese is bubbly and golden. Remove from the oven and let it cool for 5 minutes. Garnish with fresh parsley and serve warm.