Preheat the oven to 375 degrees F. Grease a 9 x 13-inch baking dish with nonstick spray and set aside.
In a large bowl, combine the beef, breadcrumbs, egg, onion, nutmeg, garlic powder, salt, and pepper. Mix well until just combined. Scoop and roll 1 ½ tablespoons of the mixture into a ball. Repeat with the remaining mixture.
Heat olive oil in a large skillet over medium-high heat. Add the meatballs and cook until all sides are browned. Transfer the meatballs to a plate and set aside.
Cook the noodles in a large pot of salted boiling water for two minutes less than the package directions.
In the now-empty skillet, add the broth, heavy cream, and Worcestershire sauce. Scrape up any browned bits on the bottom of the pan and allow the mixture to simmer for about 10 minutes until slightly thickened. Season with salt and pepper to taste, then remove from heat.
In the prepared baking dish, add the pasta and top with meatballs. Pour the sauce evenly over the pasta and meatballs, then sprinkle with cheese.
Bake in the preheated oven for about 20 minutes or until the cheese has melted and is bubbly. Remove from the oven and let the casserole sit for about 5 minutes.
Serve and enjoy!
