Preheat the oven to 350 degrees and prepare a 9x13 casserole dish with a light coating of cooking spray.

In a large bowl, mix together the shredded hash browns, vegetables, chicken, cream of chicken soup, sour cream, milk, 1/4 cup melted butter, 1 cup shredded cheese, seasoned salt, garlic powder and black pepper.

Spread the mixture into the prepared casserole dish and top with remaining 1 cup shredded cheese.

In a small bowl, mix the Ritz crackers with remaining 1/4 cup melted butter and sprinkle over the cheese layer on the casserole.

Cover with foil and bake for 45 minutes. Remove cover and bake for an additional 15 minutes or until the top is golden brown and the casserole is hot and bubbly.

Serve topped with fresh sliced green onions and chopped parsley for garnish.