Preheat the oven to 375°F (190°C).

In a large skillet over medium heat, cook the ground beef and diced onion until the beef is fully browned and the onion is softened.

Drain any excess fat from the skillet.

Stir in the condensed soup and sour cream until well combined and heated through.

Season the mixture with salt and black pepper; add optional garlic powder or paprika if desired.

Spread the beef mixture evenly across the bottom of a lightly greased casserole dish.

Sprinkle one cup of shredded Cheddar cheese over the beef mixture.

Arrange the frozen tater tots in a single layer on top of the cheese.

Place the casserole in the oven and bake for 25–30 minutes until the tater tots are starting to brown.

Remove the casserole from the oven and sprinkle the remaining shredded Cheddar over the tater tots.

Return to the oven and bake an additional 5 minutes, or until the cheese is melted and bubbly.

Let the casserole rest for a few minutes before serving warm.