Preheat your oven to 350°F (175°C).

In a large pot, bring salted water to a rolling boil. Add 12 ounces of pasta and cook until al dente, about 8-10 minutes. Drain and set aside.

In a large skillet over medium heat, melt 4 tablespoons of unsalted butter. Add 4 cloves of minced garlic and sauté for about 1 minute until fragrant.

Sprinkle 1 tablespoon of all-purpose flour over the garlic and butter mixture, stirring for about 1 minute.

Gradually whisk in 2 cups of heavy cream and 1 cup of broth, cooking until the sauce thickens, about 5-7 minutes.

Mix in 1 teaspoon of Italian seasoning, 1 teaspoon of salt, and ½ teaspoon of black pepper. Adjust seasoning if necessary.

Reduce heat to low and stir in 1 cup of grated Parmesan cheese until melted and smooth.

Add the cooked pasta to the sauce and mix gently to coat.

Transfer the mixture into a greased 9x13 inch baking dish.

Sprinkle 1 cup of shredded mozzarella cheese over the top.

Bake for 20-25 minutes until bubbling and golden brown.

Let cool for 5 minutes before garnishing with fresh parsley and optional red pepper flakes.