In a large bowl, combine ground beef, bread crumbs, milk, diced onions, garlic powder, and allspice. Mix well until fully integrated, then form the mixture into small meatballs, about one inch in diameter. Chill the meatballs in the refrigerator for 30 minutes to help them firm up.

Heat a skillet over medium heat and add a drizzle of oil. Once hot, carefully place the meatballs in the skillet, making sure not to overcrowd them. Cook for about 6-8 minutes, turning occasionally until browned on all sides. Transfer the cooked meatballs to a plate and set aside.

In a large pot, bring salted water to a boil. Add your chosen pasta and cook according to package instructions until al dente, usually around 8-10 minutes. Drain the pasta and reserve a cup of the pasta water, then set the pasta aside in the pot to keep warm.

In a medium saucepan over medium heat, melt butter until foamy. Whisk in flour and cook for 1-2 minutes until golden brown. Gradually add beef broth and Worcestershire sauce, whisking constantly until the mixture thickens and bubbles, approximately 5-7 minutes.

Lower the heat and fold the cooked meatballs into the thickened sauce, gently ensuring they are well-coated. Add the cooked pasta to the sauce mixture and toss to combine. If the mixture seems dry, you can add a splash of reserved pasta water.

Preheat your oven to 350°F (175°C). Transfer the mixture into a greased baking dish, spreading it evenly. If desired, sprinkle cheese on top. Bake in the oven for approximately 20-30 minutes or until bubbly and golden brown on top.

Once out of the oven, let the dish cool for about 5 minutes before serving. Serve alongside a crisp salad or crusty bread.