Bring a large pot of salted water to a boil. Add 2 cups of penne pasta and cook according to package instructions until al dente. Drain and set aside.
Heat 1 tablespoon of olive oil in a large skillet over medium heat. Add the cubed chicken breast, sprinkle with garlic powder, onion powder, salt, and pepper. Cook, stirring occasionally, until the chicken is browned and cooked through, about 6-8 minutes. Remove from heat.
In a mixing bowl, combine 1 cup of buffalo sauce and 1 cup of ranch dressing. Stir until smooth and well blended.
In the same large pot or a large bowl, mix the cooked penne pasta with the sautéed chicken. Pour the buffalo ranch sauce over the pasta and chicken, stirring gently to coat everything evenly.
Preheat your oven to 375°F (190°C). Lightly grease a 9x13-inch baking dish. Transfer the pasta, chicken, and sauce mixture into the dish. Sprinkle the shredded cheddar and mozzarella cheeses evenly on top.
Place the baking dish in the oven and bake for 20-25 minutes, or until the cheese is melted, bubbly, and golden brown on top.
Remove from the oven and let it rest for a few minutes. Sprinkle chopped green onions over the top for a fresh burst of flavor. Serve hot and enjoy!