Cook the Ground Beef: In a large skillet, heat olive oil over medium heat. Add the ground beef and cook until browned, breaking it up as it cooks. Drain excess fat and season with garlic powder, onion powder, salt, and pepper. Stir in the ranch seasoning mix and set aside.
Prepare the Sauce: In a separate saucepan, combine the cream cheese, sour cream, and milk over medium heat. Stir until the cream cheese is fully melted and the mixture is smooth. Add the shredded cheddar cheese and continue stirring until the cheese is melted and the sauce is creamy. Season with a pinch of salt and pepper to taste.
Assemble the Bake: Preheat your oven to 375°F (190°C). In a large mixing bowl, combine the cooked rotini pasta, beef mixture, sweet corn, and cheese sauce. Stir until everything is well combined.
Bake the Dish: Transfer the mixture to a greased 9×13-inch baking dish. Spread the top evenly and sprinkle a little extra shredded cheddar cheese on top for extra cheesy goodness.
Bake and Serve: Bake for 20-25 minutes, until the top is golden and bubbly. Garnish with fresh parsley before serving.