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. Season the chicken pieces with salt, black pepper, and garlic powder. Add the chicken to the skillet and cook for about 5-7 minutes, or until golden brown and cooked through.
While the chicken is cooking, in a small bowl, whisk together the honey, soy sauce, apple cider vinegar, and crushed red pepper flakes if using.
Once the chicken is cooked, add the sliced bell peppers to the skillet and stir-fry for about 2-3 minutes until they are slightly tender.
Pour the honey mixture over the chicken and bell peppers. Stir well to coat everything evenly and let it simmer for about 2-3 minutes until the sauce thickens slightly.
Add the cooked penne pasta to the skillet and toss everything together until the pasta is well coated with the sauce. Cook for an additional 1-2 minutes to heat through.
Remove from heat and garnish with chopped green onions before serving.