Cook the penne pasta according to package instructions until al dente. Drain and set aside.
In a large skillet, heat the olive oil over medium-high heat. Add the chicken pieces, salt, black pepper, and garlic powder. Cook until the chicken is browned and cooked through, about 6-8 minutes.
In a small bowl, whisk together the honey, soy sauce, apple cider vinegar, and red pepper flakes (if using). Pour the sauce over the cooked chicken in the skillet and stir to coat. Let it simmer for 2-3 minutes until the sauce thickens slightly.
Add the sliced bell peppers to the skillet and cook for an additional 2-3 minutes until they are tender but still crisp.
Toss the cooked pasta into the skillet with the chicken and sauce, mixing well to combine.
Serve hot, garnished with chopped green onions and sesame seeds if desired.