Once the skillet is hot, add chicken and cook until browned on both sides and temperature reaches 165℉.
Remove chicken to a separate plate and rest for 5-10 minutes. Wipe skillet clean, if needed.
While chicken is cooking, cook pasta until al dente. Drain and toss with some olive oil to prevent the pasta from sticking. Set aside.
Add marinara sauce to the same skillet; add garlic powder (if desired). Add cooked pasta and chicken to sauce and toss to combine.