Step 1: Prepare the Pasta and Chicken

1. Cook the Pasta: In a large pot of salted boiling water, cook the pasta according to package instructions until al dente. Drain and set aside. Avoid overcooking the pasta, as it will continue to cook in the oven.
2. Season and Cook the Chicken: While the pasta is cooking, heat 1 tablespoon of olive oil in a large skillet over medium-high heat. Add the bite-sized chicken pieces, then season with salt, black pepper, and Italian seasoning. Cook for about 5-6 minutes, stirring occasionally, until the chicken is cooked through and lightly browned. Remove the chicken from the skillet and set aside.

Step 2: Make the Creamy Garlic Parmesan Sauce

1. Melt the Butter: In the same skillet, melt 3 tablespoons of butter over medium heat. Add the minced garlic and cook for about 1 minute, until fragrant. Be careful not to let the garlic burn.
2. Make the Roux: Sprinkle the flour over the garlic and butter mixture, stirring constantly to combine. Cook the flour for 1-2 minutes to eliminate any raw taste.
3. Add the Milk and Cream: Slowly whisk in the milk and heavy cream, stirring constantly to avoid lumps. Continue to cook for 3-5 minutes, or until the sauce begins to thicken.
4. Add the Parmesan: Stir in 1 cup of grated Parmesan cheese, salt, black pepper, and red pepper flakes if using. Continue to whisk until the cheese melts and the sauce becomes smooth and creamy. Taste and adjust the seasoning as needed.
5. Combine with Pasta and Chicken: Add the cooked pasta and chicken to the skillet with the sauce. Gently stir to coat everything evenly with the creamy garlic Parmesan sauce.

Step 3: Assemble the Pasta Bake

1. Preheat the Oven: Preheat your oven to 350°F (175°C).
2. Transfer to Baking Dish: Pour the creamy chicken and pasta mixture into a 9×13-inch baking dish, spreading it out evenly.
3. Prepare the Topping: In a small bowl, combine the breadcrumbs, grated Parmesan, and olive oil. Mix well until the breadcrumbs are evenly coated with the oil. This will help them turn golden and crispy in the oven.
4. Add the Topping: Sprinkle the breadcrumb mixture evenly over the top of the pasta. This will create a crunchy layer that contrasts beautifully with the creamy pasta underneath.

Step 4: Bake the Pasta

1. Bake: Place the baking dish in the preheated oven and bake for 20-25 minutes, or until the topping is golden brown and the sauce is bubbly.
2. Optional Broiling: For an extra-crispy topping, turn on the broiler for the last 1-2 minutes of baking. Keep a close eye on it to prevent burning.
3. Garnish and Serve: Remove the pasta bake from the oven and let it cool for a few minutes. Garnish with fresh parsley for a pop of color, if desired. Serve hot, and enjoy!