Step 1: Add the Chicken to the Crockpot - Place the six boneless skinless chicken thighs in the bottom of your crockpot. I usually spread them out as evenly as I can rather than piling them into one big mound. This helps everything cook at a similar rate. You do not need to brown the chicken first, which is one of the reasons I like this meal on busy days. The slow cooker will take care of getting those thighs tender while you move on with the rest of your afternoon.
Step 2: Season the Chicken - Sprinkle the black pepper, red pepper flakes, and garlic powder evenly over the chicken thighs. Try to get a little seasoning over every piece rather than dumping it all in one spot. The red pepper flakes are not there to make dinner fiery. That small pinch simply adds enough warmth to balance the rich cream cheese and cheddar later.
Step 3: Pour in the Chicken Broth - Pour one cup of chicken broth around and over the seasoned chicken. The broth provides the liquid the chicken needs as it cooks and eventually becomes part of your creamy sauce. Do not worry if it does not look like much liquid at this point. The chicken will release additional juices while cooking, and the softened cream cheese will eventually make everything considerably richer and thicker.
Step 4: Add the Cream Cheese and Ranch - Place the cream cheese over the chicken, then sprinkle the ranch seasoning over the top. You can leave the cream cheese in blocks rather than trying to stir it into the cold broth. It will soften as the crockpot heats. Once the chicken finishes cooking, everything will be much easier to combine. This is one of those moments when doing less actually works better.
Step 5: Slow Cook Until Tender - Cover the crockpot and cook everything on high for 3 to 4 hours. The exact timing can vary a little depending on your slow cooker and the size of your chicken thighs. What you are looking for is fully cooked chicken that shreds easily with two forks. If the chicken is fighting you when you try to pull it apart, give it a little more cooking time.
Step 6: Cook the Bacon - While the chicken cooks, prepare the bacon until crisp. You can do this in a skillet or use your preferred bacon cooking method. Let it cool, then refrigerate it until you are ready to finish the pasta. I like handling this earlier because it means there is one less pan demanding my attention right when everybody starts wandering into the kitchen asking when dinner will be ready.
Step 7: Shred the Chicken and Melt in Cheddar - Once the chicken is tender, use two forks to shred it directly in the crockpot. Stir the chicken into the softened cream cheese, broth, ranch seasoning, and cooking juices until you have a thick, creamy mixture. Add one cup of shredded cheddar cheese and stir again. Give the cheese a minute to melt into the hot sauce. At this point, the crockpot should smell like the kind of dinner that gets people into the kitchen without being called twice.
Step 8: Boil the Penne Until Al Dente - Bring a large pot of water to a boil and cook the penne according to the package directions until al dente. You want the pasta tender but still firm enough to have some bite. This matters because the noodles will spend a little time sitting in the hot sauce after you add them to the crockpot. Pasta that starts out too soft can become mushy quickly.
Step 9: Drain and Add the Pasta - Drain the cooked penne well, then add it directly to the crockpot with the chicken mixture. You do not need to rinse the pasta. Stir gently but thoroughly until the noodles are coated with sauce and the shredded chicken is distributed throughout the pot. Take your time here and scrape around the edges and bottom so every scoop gets a good combination of chicken, pasta, and sauce.
Step 10: Add the Remaining Cheese - Sprinkle the remaining one cup of shredded cheddar cheese evenly over the top of the pasta. Put the lid back on for a few minutes so the heat from the crockpot can soften and melt the cheese. You are looking for a warm cheesy blanket across the top rather than anything browned or crisp.
Step 11: Finish With Bacon and Green Onions - Chop the cooked bacon into bite sized pieces and scatter it across the melted cheddar. Chop the green onions and sprinkle them over the top according to your family's preference. I usually put a generous amount on my serving because that fresh onion flavor is great with the creamy sauce. If the kids are not interested in green onions, you can easily leave part of the crockpot uncovered and let everyone add their own.