Preheat the oven to 375°F (190°C).
Gather all ingredients.
Thinly slice the potatoes to about 1/8-inch thickness.
In a skillet, cook the Kielbasa sausage over medium heat until browned, about 5-7 minutes.
In a mixing bowl, combine sour cream, garlic powder, black pepper, and any other desired seasonings.
Layer sliced potatoes, cooked Kielbasa, and creamy sauce in a greased casserole dish.
Sprinkle shredded cheese over the top layer.
Cover with aluminum foil and bake for 45 minutes, then remove foil and bake for an additional 15-20 minutes.
Let the casserole rest for 10 minutes before serving.
Serve warm and enjoy!