Brown meat and onion in skillet. Stir in tomatoes, oregano, salt and pepper. Bring to boil. Simmer, uncovered, stirring occasionally, 20 minutes. Remove from heat and add mozzarella and 1/4c parmesan. Let stand 9-12 minutes. Meanwhile, cook fettucine. Beat egggs, stir in remaining parmesan, butter, parsley and garlic powder. Stir into hot noodles. Spoon onto tomato mixture. Cover. Cook over low heat, 15 minutes or until set. Let stand 5 minutes. Turn out on round platter.