01 - Preheat oven to 375°F. Lightly grease a 9x13-inch casserole dish with nonstick spray or butter.
02 - In a large mixing bowl, combine the softened cream cheese, ranch dressing, and buffalo wing sauce. Stir vigorously until the mixture is completely smooth and well blended.
03 - Fold the shredded chicken, cooked pasta, 1 1/2 cups of cheddar cheese, and 1/2 cup of mozzarella cheese into the buffalo cream base. Mix until every component is evenly coated.
04 - Transfer the entire mixture into the prepared casserole dish, spreading it into an even layer. Scatter the remaining cheddar and mozzarella over the top.
05 - If using, sprinkle the blue cheese crumbles and panko breadcrumbs evenly across the surface for extra flavor and crunch.
06 - Bake uncovered on the center rack for 30 to 35 minutes, until the cheese is melted, the edges are bubbling, and the top has turned golden brown.
07 - Remove from the oven and let rest for 5 minutes. Scatter the sliced green onions over the top and serve hot directly from the dish.