01 -
Lightly grease the inside of the slow cooker with butter or nonstick spray.
02 -
In a large bowl, whisk together soup, sour cream, milk, melted butter, garlic powder, onion powder, salt, and black pepper until smooth.
03 -
Add frozen hash browns, sliced kielbasa, diced onion, and shredded cheese into the bowl. Mix until all ingredients are evenly coated.
04 -
Pour the mixture into the prepared slow cooker and spread it out evenly.
05 -
Cover and cook on LOW for 6–7 hours or on HIGH for 3–4 hours. The casserole is done when the potatoes are tender and the mixture is hot and creamy.
06 -
About 15 minutes before serving, sprinkle extra cheese on top if desired and let it melt. Garnish with parsley or bacon if using.