Creating this Buffalo Chicken Casserole is straightforward if you follow these steps:

1. Preheat Oven: Preheat your oven to 350°F (175°C).
2. Mix Chicken and Sauce: In a large bowl, combine shredded chicken and buffalo sauce. Stir until the chicken is well coated.
3. Prepare Cheese Mixture: In another bowl, mix softened cream cheese, ranch dressing, garlic powder, onion powder, salt, and pepper until smooth.
4. Combine Pasta and Chicken: Add the cooked pasta to the chicken mixture and stir to combine.
5. Layer Ingredients: In a greased 9×13-inch baking dish, layer half of the chicken-pasta mixture. Spread half of the cheese mixture on top.
6. Add More Layers: Repeat with the remaining chicken-pasta mixture and cheese mixture.
7. Top with Cheeses: Sprinkle shredded cheddar and mozzarella cheeses evenly across the top.
8. Bake: Place the dish in the preheated oven and bake for 30-35 minutes, or until the cheese is bubbly and golden.
9. Garnish: Remove from the oven and let it cool for a few minutes. Drizzle with additional buffalo sauce and sprinkle with chopped green onions before serving.

These steps will guide you in creating this incredible casserole effortlessly.