Layered Spaghetti Casserole
["1/2 lb. spaghetti (uncooked), broken in half", "1 lb. ground beef", "3 Tbsp. olive oil", "1 large onion, chopped", "1/4 tsp. garlic powder", "1 (32 oz.) container prepared spaghetti sauce", "1 (15 oz.) container Ricotta cheese", "1 egg, beaten", "1/8 c. grated Parmesan cheese", "2 c. shredded Mozzarella cheese"]
["Prepare spaghetti according to package directions; drain.", "In a large skillet, brown ground beef; drain.", "Set beef aside."]
["ground beef", "olive oil", "onion", "garlic powder", "Ricotta cheese", "egg", "Parmesan cheese", "Mozzarella cheese"]