Slice chicken breasts lengthwise to create thinner, more even cutlets. Season both sides with Italian seasoning, garlic powder, salt, and black pepper.

Heat olive oil in a large skillet over medium-high heat until shimmering. Add seasoned chicken and cook 4 to 5 minutes per side until golden brown and the internal temperature reaches 165 degrees F. Transfer to a plate and let rest for 5 minutes.

While the chicken cooks, bring a large pot of salted water to a rolling boil. Add fettuccine and cook until al dente, 8 to 10 minutes. Reserve 1/2 cup pasta cooking water before draining.

In the same skillet used for the chicken, melt butter over medium heat. Add minced garlic and saute for 1 minute until fragrant.

Pour in heavy cream, Italian seasoning, salt, and pepper. Bring to a gentle simmer and cook 3 to 4 minutes, stirring occasionally, until slightly thickened.

Remove skillet from heat. Stir in freshly grated Parmesan until fully melted and sauce is smooth and creamy. If sauce is too thick, add a splash of reserved pasta water to loosen.

Slice rested chicken into strips or bite-sized pieces. Add drained pasta to the Alfredo sauce and toss to coat. Plate the pasta, top with sliced chicken, and garnish with fresh parsley. Serve immediately.