In a large pot, bring a generous amount of salted water to a rolling boil over high heat. Add the penne pasta and cook according to package instructions until al dente, about 8-10 minutes. Once cooked, reserve 1/4 cup of the pasta water, then drain the remaining liquid and keep the penne warm in the pot.

While the pasta cooks, heat a large skillet over medium-high heat. Add the olive oil and 2 tablespoons of butter, letting them melt together. Season the boneless chicken with salt and pepper, then add it to the skillet. Sauté the chicken for 4-5 minutes, or until it's golden brown and cooked through, stirring occasionally. Add 4 cloves of minced garlic and sauté for an additional minute, then remove the chicken from the skillet and set it aside.

In the same skillet where you cooked the chicken, lower the heat to medium. Add the remaining 2 tablespoons of butter and let it melt completely, followed by the 3 cloves of minced garlic. Sauté the garlic for about 30 seconds until fragrant, being careful not to let it brown.

Pour in 1 cup of heavy cream, stirring gently to combine with the garlic butter mixture. Allow the mixture to come to a gentle simmer. Once simmering, add the softened cream cheese, stirring continuously until it melts and forms a smooth, creamy sauce.

Stir in 1 cup of shredded mozzarella and 1/2 cup of grated Parmesan cheese, mixing until both cheeses are fully melted. Adjust the flavor with a pinch of salt and pepper to taste. Make sure the sauce remains warm but does not boil.

Return the sautéed chicken and cooked penne to the skillet with the creamy cheese sauce. Gently toss everything together until the pasta and chicken are thoroughly coated in the rich sauce. If needed, gradually add the reserved pasta water to reach your desired sauce consistency.

Once combined, remove the skillet from heat and transfer the Garlic Butter Chicken Penne to serving plates. Garnish with freshly chopped parsley and serve immediately while hot.