In bowl, stir seasoning with crushed tomatoes and water to make sauce
In separate large bowl, whisk eggs. Stir in ricotta and baby spinach.
To assemble, spread 1⁄2 cup tomato sauce on bottom of Square or Multipurpose Steamer. Top with three noodles, breaking to fit, if necessary.
Add half the spinach mixture and 1⁄2 cup sauce. Add another layer of three noodles, and remaining spinach mixture.
Top with last three noodles and remaining sauce.
Cover; microwave on high for 15 min. Uncover and sprinkle with cheese. If desired, cover and let rest for 3–5 min so lasagna can set before cutting and serving.