Your Instant Pot® just made lasagna a weeknight possibility.
Stir together the ricotta, egg, 1/3 cup Parmesan cheese and a pinch of salt and pepper in a medium bowl.
Pour 1 cup water into the bottom of a 6-quart Instant Pot® and arrange 2 lasagna sheets in an “X” shape. Break up another lasagna sheet into quarters and fill in any gaps with the pieces. Spread 1/2 cup marinara sauce over the pasta then top with half of the ricotta mixture, half of the spinach, and 1 cup mozzarella. Repeat this layering process once more (except do not add more water) then top with the last 3 sheets of pasta, the remaining 2 cups marinara sauce, 1 cup mozzarella and 1/3 cup Parmesan.
Follow the manufacturer’s guide for locking the lid and preparing to cook. Set to pressure cook on high for 25 minutes.
After the pressure cook cycle is complete, follow the manufacturer’s guide for quick release and wait until the quick release cycle is complete. Be careful of any remaining steam and unlock and remove the lid.
Allow the lasagna to rest for 10 minutes before slicing and serving.