Prep. Preheat oven to 400℉. Grease a 9x13 pan with butter or butter spray.
Season and pre-bake hashbrowns. Place frozen hash browns in the prepared pan. Pour melted butter over the top of the potatoes and sprinkle with ½ teaspoon salt and ½ teaspoon pepper. Stir ingredients together and then lay flat. Bake hashbrowns for 25 minutes and remove from the oven.
Add ham and cheese. Lower oven temperature to 350℉. Spread all shredded cheese and ham over cooked hash browns. Stir slightly to mix in.
Make egg mixture. In a medium bowl, whisk together eggs, evaporated milk, ¾ teaspoon salt, ½ teaspoon pepper, onion powder, garlic powder, and paprika. Pour egg mixture over hash browns.
Bake. Carefully place the casserole in the oven and bake for 45-50 minutes, or until eggs are set. Check at 30 minutes and cover with aluminum foil to prevent too much browning.
Cook and serve. Carefully remove the pan from the oven and let cool for 10-15 minutes. If desired, garnish the casserole with chopped green onions or chives. Serve warm.