Combine the tomato paste, canned tomatoes and their juice, salt, basil, sugar, bay leaves and water in a pot. Let simmer for about 2 1/2 hours.
Gently brown the garlic in olive oil and add the sausage meat and oregano. Stir in tomato sauce mixture and continue to simmer until cooked through.
Boil the pasta per package directions & drain.
Combine ricotta, egg, sugar and salt well in a bowl.
Sprinkle the base of a large casserole (or two small ones) with one-third cup of Parmesan cheese. Add a layer of half the tomato sauce, a layer of half the pasta and a layer of half the cheese mixture. Repeat layers and sprinkle remaining 2/3 cup Parmesan cheese on top.
Put in 375F (180C) oven for at least 20-25 minutes until piping hot.