1/4 teaspoon salt
2 1/2 cups (10 ounces) shredded mozzarella cheese
1/4 cup hot water
Cook beef in a large skillet over medium
heat, stirring until it crumbles and is no longer pink; drain.
Stir in pasta sauce.
Combine ricotta cheese with egg and salt,
Spread one-third of meat sauce in a lightly
greased 11 x 7 x 2-inch baking dish; layer with 3 noodles and
half each of ricotta cheese mixture and mozzarella cheese. (The
ricotta cheese layers will be thin.) Repeat procedure; spread
remaining one-third of meat sauce over mozzarella cheese. Slowly
pour 1/4 cup hot water around inside edge of dish. Tightly cover
baking dish with 2 layers of heavy-duty aluminum foil.
Bake at 375°F (190°C) for 45 minutes;
uncover and bake 10 more minutes.