Preheat oven to 350 F.
In a medium skillet over medium high heat, brown the sausage. Drain any fat and set aside.
In a medium mixing bowl, stir together the ricotta, egg, parmesan cheese, parsley and basil.
Spread 1/4 cup sauce of marinara sauce in the bottom of a 9 x 13" baking pan. Take 3 oven ready noodles and lay them in the bottom of the pan, leaving a small amount of space between each, to account for expanding during baking.
Top with 1/4 of the ricotta mixture, 1/4 of the sausage and approximately 1/2 cup of marinara. Use a small offset spatula to mix and smooth the mixture from edge to edge. Top with handful (approximately 1/2 cup) shredded cheese.
Top with three more lasagna sheets, 1/4 more of the ricotta and sausage and 1 cup of alfredo. Mix together and spread from edge to edge. Top with another 1/2 cup cheese.
Repeat this layering for two more layers, ending with 3 sheets of pasta. Generously spread 1 cup of marinara on top, making sure that the sheets are covered. Cover tightly with foil. Note: the individual layering is detailed right above the recipe if you have questions.
Bake in preheated oven for 45 minutes. Remove foil and top with slices of 1/4" thick slices of fresh mozzarella. Return to oven and bake for another 15-20 minutes, until melted and bubbling.
Remove from oven and let cool for 20-25 minutes before serving. If desired, pop back in oven for 5 minutes to rewarm cheese on top. Slice and serve.