Brown the ground beef in a large skillet over medium heat, breaking it up into small pieces with a spatula as it cooks. Once the beef is fully cooked, add the diced onions to the skillet and sauté for 2 to 3 minutes until the onion starts to turn translucent. Drain any excess fat and remove from the heat.

In a large mixing bowl, whisk together the cream of mushroom soup, cheddar cheese soup, sour cream, milk, garlic powder, parsley, black pepper, salt, and paprika. Add the shredded hash browns to the large bowl one handful at a time and mix until evenly coated.

Grease the bottom and sides of your crockpot with cooking spray or butter or line with a disposable liner. Layer half of the hash brown mixture in the bottom of the crockpot. Layer half of the ground beef mixture on top of the hash browns. Sprinkle half of the shredded cheddar cheese on top of the beef mixture.

Repeat the layers with the remaining hash brown mixture, beef mixture, and shredded cheddar cheese.

Cover the slow cooker and cook on HIGH for 3 hours, on LOW for 5 hours, or until the potatoes are tender and the casserole is hot and bubbly.

Garnish with green onions (optional) on top of the casserole. Serve hot and enjoy!