Boil Noodles: Bring a large pot of salted water to a boil. Cook at least 16 lasagna noodles until al dente (i.e. slightly undercooked), about 6 to 8 minutes. Drain in a colander. Coat them with a bit of olive oil, lay noodles out flat on a cookie sheet (divide layers with parchment paper), and set aside.
Prep Pans: Preheat the oven to 375°F. Grease a 9x13-inch baking dish (or two 8x8 inch dishes) with oil or cooking spray. Spread 1/2 cup of marinara sauce on the bottom of the 9x13 dish (or 1/4 cup in each 8x8 dish) in a thin layer.
Make Filling: In a large mixing bowl, stir together 1 cup mozzarella cheese (reserve the other 1 cup), 1 cup Parmesan cheese (reserve the other 1/2 cup), ricotta cheese, eggs, spinach, parsley, basil, pepper, salt, and garlic.
Roll Noodles: On each noodle, spread 1/4 cup of the cheese mixture and then 2 1/2 - 3 tablespoons of sauce. Note: You should have used up all the cheese mixture and one entire jar of sauce (3 - 3 1/2 cups) by this point, dividing them evenly among the noodles. Roll the noodles up, and place seam side down in the prepared pan(s). Squeeze them in however they fit best.
Finish Casserole: Top entire casserole(s) with the remaining jar of sauce (3 - 3 1/2 cups), remaining 1 cup mozzarella, and remaining 1/2 cup Parmesan cheese.
Bake & Serve: Bake for 25-30 minutes or until bubbly on the edges and hot in the middle. Let sit for 5-10 minutes and garnish with lots of fresh chopped herbs.
Freezer Instructions
Freeze For Later: Follow steps 1-5. (Do not bake). Wrap the casserole tightly in a few layers of plastic wrap and foil, squeezing out any excess air. Freeze for 3-6 months.Prepare From Frozen: Thaw casserole. Cook as directed in step 6.
Notes/Tips
This is a big batch recipe. It's easy to divide into two 8x8-inch dishes and freeze one for later.
If you want these to look more like individual rolls after baking, be more precise when placing the sauce and cheese on top. Just put a dollop on each roll instead of spreading it out. Or try our faster Easy Cheesy Baked Pasta that uses a similar filling and penne pasta instead.
How to Thaw Frozen Spinach:
Thaw overnight in fridge. (12+ hours)
Use cold water method. Place frozen spinach in leak-proof bag and squeeze out any air. Submerge in cold water for an hour or so. (1-2 hours)
Place block of frozen spinach on a microwave-safe plate. Use microwave’s defrost setting for fastest thawing. (5 minutes)
How to Drain Liquid from Frozen Spinach: Wrap thawed spinach in a tea towel and squeeze as much liquid from it as possible over the sink. Alternatively, you can place the spinach in a colander and press down on it to squeeze out the liquid.
Tips for Lasagna Noodles:
Use whole wheat, plain, or gluten free noodles.
Boil in salted water until al dente. Should still have a little bite to them when you taste test; do not over cook.
After boiling, lay out noodles side by side on a greased sheet pan.
Divide single layers of noodles with parchment paper.
Spray the tops of each layer of noodles with cooking spray to prevent drying out or sticking.
If you make these a few hours ahead, cover with a moist paper towel or plastic wrap until ready to use.