1. Bring a large pot of salted water to a boil. Cook the fettuccine according to package instructions until al dente, usually about 10-12 minutes. Drain and set aside, reserving ½ cup of pasta water for later.
2. In a large skillet over medium heat, add the chopped bacon. Cook until crispy, about 6-8 minutes. Use a slotted spoon to transfer the bacon to a paper towel-lined plate, leaving the rendered fat in the pan.
3. Add the olive oil and diced onion to the skillet with the bacon fat. Sauté until translucent and fragrant, about 3-4 minutes. Stir in the minced garlic and cook for another 30 seconds, careful not to burn it.
4. Raise the heat to medium-high and add the ground beef to the skillet. Season with smoked paprika, salt, and pepper. Cook, breaking it apart with a wooden spoon, until browned and cooked through, about 8-10 minutes. Drain any excess fat if needed.
5. Lower the heat to medium and stir in the butter, allowing it to melt into the beef mixture. Pour in the heavy cream and milk, stirring gently to combine. Let the sauce simmer for about 3-4 minutes, until it starts to thicken slightly.
6. Gradually whisk in the Parmesan and cheddar cheeses until smooth and creamy. Add Dijon mustard, if using, to enhance the tangy cheeseburger flavor. Adjust seasoning with salt and pepper to taste.
7. Fold in the cooked pasta, crispy bacon, and chopped dill pickles. If the sauce is too thick, add reserved pasta water a little at a time until you reach your desired consistency.
8. Cook everything together for another 2 minutes, allowing the flavors to meld. Garnish with fresh parsley before serving.

One trick Mama Lou taught me was to always taste as you go, especially when working with cream sauces. She believed that patience and attention to seasoning make all the difference between good and unforgettable. Ouma and I always remind each other of that when cooking together, especially for recipes like this that balance so many flavors.