In a bowl combine the ricotta, 1¼ cup of mozzarella, ¼ cup of parmesan, salt and pepper.
Grease the bottom of a rectangular baking dish.
Cover base with 3 lasagne sheets.
Top lasagne sheet layer with one third of the pasta sauce, one third of the baby spinach and one third of the ricotta mixture.
Layer with 3 lasagne sheets and repeat.
Cover with remaining lasagne sheets, the remaining pasta sauce, baby spinach and ricotta.
Top with ¼ cup mozzarella, sprinkle with extra parmesan.
Cover with baking paper and a microwave safe plate.
Microwave on high (power level 10) for 20 minutes.
Let stand for 10 minutes before serving.