Step 1Cook the pasta in boiling salted water about 11 minutes or until al dente. Drain, place in a large bowl and let cool slightly.
Step 2In a bowl, lightly beat the whites of the eggs with a fork (save the yolks for the bechamel sauce) and add the cheese. Stir into the pasta.
Step 3Melt the butter in a large heavy skillet and saute the onion until golden brown, about 3 to 4 minutes. Add the ground meat and cook 5 minutes, until browned, stirring occasionally.
Step 4Add tomatoes, wine, cinnamon, cloves and salt and pepper to taste. Cover and simmer 15 minutes. Remove the cover and continue to simmer until the juices are reduced, 10 to 15 minutes. Remove the meat sauce from the heat and let stand while preparing the bechamel sauce. After the sauce cools a bit, spoon off any excess fat.
Step 1Heat one-half cup butter until melted. Whisk in the flour, nutmeg and salt until blended. Cook, stirring 1 minute. Stir in the milk. Heat to boiling, stirring constantly. Boil and stir 1 minute.
Step 2Add the cheese. Heat and stir just until cheese is melted.
Step 3Blend a little of the heated sauce into the 4 egg yolks and return all to the saucepan. Heat and stir until the sauce thickens slightly and is almost at a simmer. Do not boil.
Step 4Generously butter a 12-by-2-inch-deep round baking pan or a 9-by-13-inch glass baking dish. Heat the oven to 375 degrees.
Step 5Add the pasta and spread in an even layer, then spread the cooled meat sauce over pasta. Spoon the bechamel sauce over the meat in an even layer.
Step 6Sprinkle bread crumbs over the sauce and drizzle two tablespoons melted butter over the top.
Step 7Bake 20 minutes, then reduce the oven temperature to 350 degrees and continue to bake 20 to 30 minutes until golden brown.
Step 8Cool slightly, cut into square pieces and serve.