Cook the fettuccine pasta according to package instructions in a large pot of salted boiling water. Drain the pasta and set aside.
In a skillet over medium heat, cook the chopped bacon until crispy. Remove the bacon from the skillet and drain on paper towels, leaving the bacon drippings in the skillet.
In the same skillet, add the ground beef and cook until browned. Drain excess fat if necessary.
Stir in minced garlic, onion powder, Worcestershire sauce, salt, and pepper. Cook for an additional 2 minutes until fragrant.
Reduce the heat to low and add the heavy cream to the skillet, stirring well to combine with the beef mixture.
Gradually add in the cheddar and Parmesan cheeses, stirring until melted and the sauce is smooth.
Gently mix in the cooked fettuccine pasta, ensuring it is well coated with the sauce.
Stir in the cooked bacon, reserving some for garnish if desired.
Serve immediately, garnishing with diced tomatoes and chopped parsley if using.