Cook lasagna noodles in boiling water until almost tender.
In a medium bowl combine Ricotta, Parmesan, spinach, salt, and eggs. Set aside.
Drain lasagna noodles. Rinse. Lay out noodles flat on surface.
Spread evenly with Ricotta mixture.
Carefully roll up noodles. Starting at the short end.
Pour 2 cups of spaghetti sauce in the bottom of a 9x13 pan.
Place rolls ups in pan then cover evenly with remaining sauce.
Sprinkle with Mozarella cheese.
Bake uncovered until hot and cheese melts, about 20 minutes.