Preheat oven to 375°F (190°C). Grease a 9×13-inch baking dish.
Cook the elbow macaroni according to package instructions. Drain and set aside.
In a large skillet, brown the ground beef over medium heat. Add the chopped onion and cook until softened, about 3-4 minutes. Drain any excess fat.
Stir in the crumbled bacon, ketchup, mustard, garlic powder, onion powder, and salt and pepper. Simmer for 5 minutes.
In a large bowl, combine the cooked macaroni and beef mixture. Add the milk and stir to combine.
Transfer the mixture into the prepared baking dish and top with shredded cheddar and mozzarella cheeses.
Bake for 20-25 minutes, or until the cheese is melted and bubbly.
Let cool for a few minutes before serving.
Prep Time: 10 minutes | Cooking Time: 30 minutes | Total Time: 40 minutes
Kcal: 450 kcal per serving | Servings: 6 servings