Coat a large nonstick skillet with nonstick spray and place it over medium heat.
Add the mushrooms and simmer, stirring frequently, for about 6 minutes or until they release their juice and nearly completely evaporate.
Add the spinach in small batches, season with 1/4 teaspoon salt, and use a slotted spoon to transfer to a bowl. Throw away fluids.
Add the beef, onion, and garlic; simmer and break up the meat with a wooden spoon for about 5 minutes, or until it is no longer pink.
Add the remaining 1/2 teaspoon of salt, the oregano, tomato sauce, crushed tomatoes, and pepper flakes. 5 minutes of simmering is sufficient.
Mix the ricotta, 3/4 cup mozzarella, 2 tablespoons Parmesan, and 1/4 cup basil in a medium bowl.
Spread one-third of the beef mixture in the bottom of a 6-quart slow cooker.
Lay three lasagna noodles on top of the beef, breaking them as necessary to fit.
Place a third of the mushroom mixture on top of the noodles, then sprinkle the remaining ricotta mixture on top.
Then, divide the remaining 3 noodles in half and place them on top of the beef mixture. Finish by spooning half of the remaining beef mixture on top.
Add the leftover beef, ricotta, and mushrooms on top.
For about 3 to 4 hours, simmer the noodles, covered, on LOW heat until they can be punctured with a knife.
Remove the slow cooker's lid and shut it off. Top with the remaining 3/4 cup mozzarella and 3 tablespoons of Parmesan.. Cover the slow cooker, wait until the cheese has melted, about 10 minutes,
Sprinkle the remaining 1/4 cup basil over the top and cut the lasagna into 8 portions.
Notes
8 Points (2022/2023 Plan)MyWW Points: 8 Blue Plan and 10 Green Plan8 WW Freestyle Points and 10 WW Smart PointsWe are not associated with Weight Watchers/WW in any way. Double check points on their official calculator.