Boil water in your pot.
Add salt to it.
Cook noodles until soft.
Drain them and set aside.
Brown the beef in skillet.
Break it into pieces.
Add marinara sauce and stir.
Simmer for ten minutes gently.
Combine ricotta and egg together.
Add parmesan cheese too.
Mix until smooth and creamy.
Spread sauce on dish bottom.
Add noodles in one layer.
Spread cheese mixture evenly now.
Add more sauce on top.
Repeat layers two more times.
Cover with aluminum foil tightly.
Bake at 375°F for 45 minutes.
Remove foil for last 15 minutes.
Cheese should be golden brown.