In a large bowl, combine the ground pork, ground beef, panko breadcrumbs, chopped parsley, ground allspice, minced onion, garlic powder, black pepper, salt, and egg. Mix until all the ingredients are evenly combined. Roll the mixture into small, golf ball–sized meatballs.

Heat the olive oil and 1 tablespoon of unsalted butter in a large skillet over medium heat. Add the meatballs in a single layer. Cook, turning them to brown on all sides and until they are cooked through. Transfer the meatballs to a plate and set aside.

In the same skillet, add 3 tablespoons of unsalted butter and let it melt. Stir in the flour and cook for about 2 minutes until it turns a light brown color. Slowly whisk in the beef broth and heavy whipping cream. Add the Worcestershire sauce and Dijon mustard. Allow the sauce to simmer for several minutes until it thickens slightly. Season with extra salt and pepper as needed.

Return the browned meatballs to the skillet with the sauce. Stir gently to coat the meatballs in the sauce and let them heat through.

While the sauce simmers, cook the pasta in a large pot of boiling salted water until al dente. Drain the pasta and then toss it with the meatball sauce. If the sauce is too thick for your liking, add another splash of broth or cream and stir to combine.

Garnish with extra chopped parsley and serve immediately.