Preheat oven to 350°. Grease a 2 quart casserole dish, and set aside.
Bring a large pot of lightly salted water to a boil. Peel the potatoes, slice potatoes in half. Cook potatoes in boiling water until tender. Drain, and transfer to a large mixing bowl.
Mash the potatoes until smooth, stir in the sour cream, cream cheese, onion salt, garlic powder and chives.
Pour into the greased casserole dish and spread out evenly.
Mix the butter and the dry bread crumbs together and sprinkle evenly over the potatoes.
Bake for 40-50 minutes until it is heated through.
Top with the grated cheese and garnish with chopped green chives and serve.