Bring a pot of salted water to a boil and cook the penne pasta according to package instructions until al dente. Drain and set aside.
In a large mixing bowl, combine the shredded rotisserie chicken, buffalo sauce, ranch dressing, cooked pasta, garlic powder, onion powder, salt, and pepper. Mix until well combined.
Gently fold in the green onions, cherry tomatoes, and half of the shredded cheddar cheese.
Lightly grease a 9x13 inch baking dish with olive oil. Pour the pasta mixture into the dish and spread it out evenly.
Top with the remaining shredded cheddar cheese and the crumbled blue cheese if using.
Cover the dish with aluminum foil and bake in the preheated oven for 20 minutes.
Remove the foil and bake for an additional 10 minutes, or until the cheese is bubbly and golden brown.
Once done, remove from the oven and let it cool for a few minutes.
Garnish with extra chopped green onions and serve warm.
Notes
Serve hot, garnished with extra ranch dressing and parsley for added color.