Preheat oven to 350°. In a large bowl, beat cream cheese and sour cream until smooth. Beat in soup, onion powder and garlic powder. Stir in chicken and cottage cheese. Transfer to a greased 9-in. square baking dish. Combine crackers and butter; sprinkle over casserole. , Bake, uncovered, until heated through, 25-30 minutes. Sprinkle with green onions.