Bring a large pot of generously salted water to a rolling boil. Add the penne pasta and cook until exactly al dente (about 10-12 minutes). Reserve 1/2 cup of the starchy pasta water, then drain the pasta and set aside.

Pat the chicken breasts dry and season both sides with Italian seasoning, garlic powder, salt, and black pepper. Heat olive oil in a large skillet over medium-high heat. Sear the chicken for 5-7 minutes per side until a deep golden-brown crust forms and it reaches 165°F (74°C) internally. Remove and let rest.

Reduce heat to medium-low. Add butter to the same skillet to melt. Add minced garlic and sauté for 30 to 60 seconds until fragrant. Pour in the chicken broth, scraping up all the browned bits from the bottom of the pan.

Slowly pour in the heavy cream and bring to a gentle simmer. Gradually sprinkle in the grated parmesan cheese, stirring continuously until melted and the sauce turns a rich, off-white color. Simmer for 2-3 minutes until thickened.

Toss the cooked penne in the cream sauce. Slice the rested chicken into strips and place over the pasta. Garnish generously with the chopped sun-dried tomatoes and finely minced fresh parsley before serving.