Slice the chicken breasts horizontally into thinner pieces so they cook evenly. Season both sides with salt, black pepper, Italian seasoning, and garlic powder.

Heat the olive oil and 1 tablespoon of butter in a large skillet over medium-high heat. Add the chicken and cook for several minutes per side, until golden brown and cooked through. Transfer the chicken to a clean plate.

Bring a large pot of salted water to a boil. Cook the fettuccine or linguine according to the package directions until al dente. Reserve 1/2 cup of pasta water, then drain the pasta.

Add 2 tablespoons of butter to the same skillet. Add the sliced mushrooms and cook for several minutes, stirring occasionally, until tender and golden brown.

Add the minced garlic and cook for about 30 seconds, stirring constantly, until fragrant.

Pour the Marsala wine into the skillet. Scrape the browned bits from the bottom of the pan with a wooden spoon. Simmer for 2 to 3 minutes to reduce the wine slightly.

Add the chicken broth and bring the mixture to a gentle simmer. Cook for another 2 to 3 minutes.

Reduce the heat to medium-low and pour in the heavy cream. Add the Italian seasoning and black pepper. Simmer gently for 3 to 5 minutes, stirring occasionally, until the sauce begins to thicken.

Stir in the freshly grated Parmesan cheese and continue stirring until the cheese melts into the sauce.

Add the cooked pasta to the skillet and toss until the noodles are evenly coated with the creamy Marsala sauce. If the sauce is too thick, gradually add a little reserved pasta water.

Slice the cooked chicken into strips and place it over the pasta, or gently toss the chicken into the sauce.

Garnish with freshly chopped parsley and additional Parmesan cheese. Serve immediately while hot.