Preheat the oven to 375°F (190°C) and lightly grease a 9x13-inch ceramic or glass baking dish with non-stick cooking spray.

Place a large skillet over medium-high heat. Add the ground beef and diced onion, cooking until the beef is fully browned and the onions are translucent, approximately 8 minutes.

Drain the excess rendered fat from the skillet. Stir in the minced garlic, smoked paprika, salt, and pepper, and cook for an additional 60 seconds until fragrant.

Reduce the heat to low. Add the condensed cream of mushroom soup, sour cream, and milk to the skillet. Stir until the mixture is uniform and creamy.

Fold in the drained corn and 1 cup of the shredded cheddar cheese. Continue stirring until the cheese is just melted and integrated into the sauce.

Transfer the beef mixture to the prepared baking dish, spreading it into an even layer using a spatula.

Arrange the frozen tater tots in tight, uniform rows across the entire surface of the beef mixture to ensure maximum crispness.

Transfer the dish to the center rack of the oven and bake for 25 to 30 minutes, or until the tater tots are golden brown and the edges are bubbling.

Sprinkle the remaining 1 cup of shredded cheddar cheese evenly over the tater tots. Return the dish to the oven for 5 minutes until the cheese is fully melted and bubbly.

Remove from the oven and allow the casserole to rest for 5 minutes before serving to let the sauce set.