- 2 pounds skinless, boneless chicken breasts
- 1 (1 ounce) package dry ranch dressing mix (such as Hidden Valley Ranch®)
- 1 pound bacon
- 1 green bell pepper, chopped (optional)
- 2 (15 ounce) jars Alfredo sauce, divided
- 1/3 cup milk
- 2 cloves garlic, minced
- 1 (16 ounce) package penne pasta
- 4 cups shredded mozzarella cheese
- Preheat oven to 375 degrees F (190 degrees C). Line a baking sheet with parchment paper. Arrange chicken on the baking sheet.
- Bake chicken in the preheated oven until no longer pink in the center and the juices run clear, about 30 minutes. An instant-read thermometer inserted into the center should read at least 165 degrees F (74 degrees C).
- Dice chicken and place in a bowl; add ranch mix and stir until coated.
- Place bacon in a large skillet and cook over medium-high heat, turning occasionally, until evenly browned, about 10 minutes. Drain bacon slices on paper towels, reserving bacon grease in the skillet. Crumble bacon into small pieces.
- Heat reserved bacon grease in the skillet; cook and stir bell pepper until slightly tender, 2 to 3 minutes. Add chicken, 1 jar Alfredo sauce, milk, and garlic; cook and stir until heated through, about 5 minutes.
- Bring a large pot of lightly salted water to a boil; add penne and cook, stirring occasionally, until tender yet firm to the bite, about 11 minutes. Drain.
- Pour 1/2 the jar of remaining Alfredo sauce into a casserole dish; top with 1/2 of the penne, 1/2 of the chicken mixture, 1 1/2 cup mozzarella cheese, and 1/2 of the bacon. Repeat layering with remaining ingredients in the same order ending with 1 cup mozzarella cheese and bacon on top.
- Bake in the preheated oven until casserole is bubbling and cheese is lightly browned, about 30 minutes.