Prepare the crockpot: Spray the insert with nonstick spray.
This helps prevent sticking and makes cleanup easier.
Mix the creamy base: In a large bowl, whisk together the cream of chicken soup, sour cream, melted butter, garlic powder, salt, pepper, and broth (or milk) until smooth.
Add the cheese and onions: Stir in 1.5 cups of the shredded cheddar and the diced onion until evenly combined.
Fold in the hashbrowns: Add the frozen hashbrowns and gently fold until everything is coated. Don’t overmix or the potatoes can break down.
Load the crockpot: Transfer the mixture to the crockpot and spread it into an even layer. Sprinkle the remaining 1/2 cup cheddar on top.
Cook low and slow: Cover and cook on Low for 4–5 hours or on High for 2–3 hours, until hot throughout and the edges are bubbly.
Stir once about halfway through if you like a more even texture.
Add a crunchy topping (optional): If using crackers or cornflakes, mix with melted butter and sprinkle over the top during the last 30 minutes of cooking so it warms and crisps slightly.
Finish and serve: Taste and adjust salt if needed. Let it sit uncovered for 5–10 minutes to set, then scoop and serve warm.