01 - Set the oven to 375°F (190°C) to prepare for baking.
02 - Boil a large pot of salted water and cook macaroni according to package directions until al dente. Drain and set aside.
03 - In a large skillet over medium heat, cook diced bacon until crispy. Remove using a slotted spoon and set aside.
04 - In the same skillet, cook ground beef over medium heat until browned and fully cooked, breaking it apart with a spoon. Drain excess fat.
05 - Melt 3 tablespoons of butter in a saucepan over medium heat. Whisk in flour and cook for 1 minute to form a roux.
06 - Gradually whisk in whole milk, stirring constantly until smooth. Cook until sauce thickens, about 5 minutes.
07 - Remove sauce from heat and stir in grated cheddar, mozzarella, Dijon mustard, garlic powder, onion powder, black pepper, and salt until smooth and melted.
08 - In a large bowl, mix cooked macaroni, crispy bacon, ground beef, and cheese sauce until evenly coated.
09 - Grease a 9x13 inch baking dish and transfer the mac and cheese mixture into it.
10 - Mix panko breadcrumbs with melted butter. Sprinkle evenly over the macaroni mixture. Bake for 15-20 minutes until the topping is golden and bubbling.
11 - Sprinkle chopped fresh parsley on top before serving.