Preheat your oven to 375°F and lightly grease a 9x13-inch baking dish with cooking spray.
In a skillet, cook the ground beef, breaking it into small pieces, until it is no longer pink. Drain any excess grease.
In a large mixing bowl, whisk together the cream of mushroom soup, milk, and sour cream until smooth.
Add the onion powder, salt, and black pepper, stirring until everything is well combined.
Using a wooden spoon, mix in the cooked ground beef, corn, ½ cup of cheddar cheese, and bacon until evenly incorporated.
Transfer the mixture into the prepared baking dish. Top with ½ cup of cheese and layer the tater tots over the top.
Bake for 40 minutes, or until the casserole is bubbly and the tater tots are golden brown.
Sprinkle the remaining ½ cup of cheese on top and return to the oven for about 5 minutes, until the cheese is melted.
Serve with an extra sprinkle of bacon on top, if desired.