In a large pot of boiling water, cook penne pasta until al dente, according to package directions. Drain.
Season chicken pieces with ranch seasoning. Spray a large non-stick skillet with cooking spray.
Cook chicken in prepared skillet over medium-high heat until no longer pink in center; about 10 to 12 minutes. Carefully transfer cooked chicken to a large plate. Tent with foil to keep warm. Carefully wipe skillet clean so you can cook the sauce in it.