Cook chopped bacon in a large skillet over medium heat until crispy, 5–7 minutes. Transfer to a paper towel–lined plate, leaving about 1 tablespoon of bacon grease in the skillet.

Add ground beef and diced onion to the skillet and cook until the beef is browned and the onion softens, about 7 minutes.

Drain excess fat if needed, then stir in garlic, ketchup, mustard, Worcestershire sauce, smoked paprika, salt, and pepper. Cook for 2 minutes more.

Boil ramen noodles (discard the seasoning packet) for 2 minutes until slightly undercooked. Drain and set aside.

In a large bowl, whisk together condensed cheddar soup, sour cream, and milk until smooth. Stir in shredded cheddar and mozzarella, then mix in the noodles, beef mixture, and half of the cooked bacon until evenly coated.

Preheat oven to 350°F (175°C). Grease a 9×13-inch baking dish and spread the beef-and-noodle mixture evenly inside.

Top with the remaining cheddar, then sprinkle crushed tortilla chips or breadcrumbs, and finish with the remaining bacon.

Bake for 20–25 minutes until the cheese is melted and bubbly. Let rest for 5 minutes before serving. Garnish with chopped green onions if desired.