Preheat oven to 350°. In a large skillet, cook bacon until crisp. Remove with a slotted spoon to paper towels. Drain, reserving ⅓ cup drippings. In the drippings, saute onion until tender. Stir in the flour, salt and pepper until blended. Gradually stir in milk. Bring to a boil; cook and stir for 2 minutes or until thickened. Remove from the heat.
Spread ½ cup sauce in a greased 13x9-in. baking dish. Layer with 4 noodles and a third each of the eggs, bacon, Swiss cheese and remaining sauce. Repeat layers twice. Sprinkle with Parmesan cheese.
Bake, uncovered, until bubbly, 35-40 minutes. If desired, sprinkle with parsley. Let stand for 15 minutes before cutting.
