Bring a large pot of salted water to a boil. Add the penne pasta and cook until al dente according to the package instructions, usually about 10-12 minutes. Drain and set aside.
In a large skillet over medium heat, add the chopped turkey bacon. Cook until crispy, about 5 minutes. Remove and set aside on a paper towel-lined plate. In the same skillet with the rendered bacon fat, add the diced onion and cook until softened, about 3-4 minutes. Stir in the minced garlic and cook for another 30 seconds until fragrant.
Add the ground beef to the skillet with onions and garlic. Break it up with a spatula and cook until browned and cooked through, about 7-8 minutes. Drain any excess fat if necessary.
Return the turkey bacon to the skillet. Stir in the undrained diced tomatoes, beef broth, mustard, Worcestershire sauce, salt, and pepper. Let the mixture simmer for 5-7 minutes to meld the flavors and slightly reduce the liquid.
Add the cooked penne pasta to the skillet and toss everything together until well combined. If your skillet isn’t ovenproof, transfer the mixture to a greased 9x13-inch baking dish.
Sprinkle the shredded cheddar and mozzarella evenly over the top of the pasta mixture. Place the baking dish in a preheated oven at 375°F (190°C) and bake uncovered for 20-25 minutes, or until the cheese is melted, bubbly, and golden brown on top.
Remove from the oven and let cool slightly. Garnish with fresh parsley if desired before serving.