Cut the chicken breasts into bite-sized pieces to ensure even cooking throughout the slow cooker. In a small bowl, combine the garlic powder, onion powder, and salt—this ensures the seasonings distribute evenly rather than clumping. Place the cut chicken pieces directly into your crockpot and sprinkle the seasoning mixture over them, stirring gently to coat all pieces.

Place the softened cream cheese directly onto the seasoned chicken in the crockpot. In a separate bowl, whisk together the chicken broth and half and half until well combined and smooth. Pour this mixture over the chicken and cream cheese. The cream cheese will soften and blend into the sauce as it cooks, creating a silky base. I find that having the cream cheese at room temperature before adding it helps it incorporate more smoothly into the sauce.

Cover the crockpot and cook on high for 2 hours or on low for 3 to 4 hours. The chicken is done when it reaches an internal temperature of 165°F and shreds easily with a fork. The longer, slower cooking method on low will give you more tender, flavorful chicken, but high heat works well if you're short on time.

While the chicken is cooking during the last 15 minutes or so, bring a large pot of salted water to a boil and cook the penne according to package directions until al dente—usually about 9-10 minutes. Drain the pasta well and set aside. Once the chicken is fully cooked and tender, carefully remove it from the crockpot using a slotted spoon, transferring it to a clean cutting board and covering it loosely with foil to keep it warm. This prevents the chicken from overcooking while you finish the sauce.

Add the cooked al dente penne directly into the slow cooker with the cream sauce. Stir well to coat all the pasta. Cook uncovered for 20-25 minutes on high, stirring occasionally, until the pasta absorbs some of the sauce and the mixture thickens slightly. The pasta will continue to soften and the flavors will meld together during this time.

Shred the reserved warm chicken into bite-sized pieces using two forks or your hands. Add the shredded chicken back into the slow cooker along with the butter, Parmesan cheese, and nutmeg. Stir everything together until the butter melts completely and the cheese is fully incorporated and creates a cohesive, creamy sauce. I prefer freshly grated Parmesan for this step because it melts more smoothly and gives a better texture than pre-shredded varieties, which often contain anti-caking agents.

Taste the alfredo and adjust the seasoning as needed. Add additional salt and pepper to your preference. The nutmeg should provide a subtle warmth without being overpowering. Serve immediately while hot and creamy, directly from the crockpot or transferred to serving bowls.