Ingredients chopped frozen spinach, thawed and squeezed to remove excess moisture ricotta grated Parmesan cups marinara sauce lasagna noodles grated mozzarella onion, thinly sliced (optional) Directions In a bowl, mix together the spinach, ricotta, and some of the Parmesan. Spread some of the marinara in the bottom of a slow cooker. Top with noodles (breaking to …