Step 1: Preheat oven to 400 degrees.
Step 2: Add breadcrumbs, milk, egg, onion, allspice, nutmeg, garlic, salt, and black pepper to a large bowl. Beat until ingredients are incorporated, and let the mixture sit for 5 minutes.
Step 3: Add pork and ground beef to the breadcrumb mixture. Combine ingredients and form the meatball mixture into 12 - 15 balls. Place the meatballs on a greased sheet pan and bake for 15 minutes, turning the meatballs halfway through the cooking process.
Step 5: Add half of the beef broth. The sauce will thicken quickly. Add the rest of the beef broth and the half and half, pepper, garlic powder, onion powder, and salt. Continue to cook until the sauce thickens, stirring often. It should take 5 - 7 minutes.
Step 6: Add the meatballs to the sauce once the sauce has thickened. Simmer for an additional 5-10 minutes over low heat. When the meatballs are 165 degrees, you'll know they are cooked through.