Quick-Baked Vegetarian Spinach Lasagna

Name: Quick-Baked Vegetarian Spinach Lasagna
Prep time: 15 min
Cook time: 40 min
Ingredients: 16 ounces frozen chopped spinach, defrosted and squeezed dry* (see below for how to best do this); 16 ounces ricotta cheese (low fat or whole milk, about 2 cups); 2½ cups shredded low-moisture mozzarella cheese (divided); ¼ cup grated Parmesan cheese; 1 teaspoon garlic powder; 1 teaspoon Italian seasoning; ½ teaspoon kosher salt; ¼ teaspoon ground black pepper; 1 large egg (lightly beaten); 3 cups pasta sauce; ¾ pound no-boil lasagna noodles (sometimes called "oven ready noodles")

by Taesha Butler on November 6, 2023

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5 from 3 votes

This is truly the easiest spinach lasagna recipe you’ll come across. No veggie chopping or noodle boiling required, yet you’ll enjoy a deliciously cheesy and flavorful dinner in just 40 minutes. Made with frozen spinach, oven-ready noodles, and just the right amount of sauce, cheese, and seasoning. This is sure to become your new go-to vegetarian lasagna recipe!

Hand holding a serving utensil taking a piece of lasagna out of a white casserole dish. Plates, utensils, basil, a napkin, and a small bowl of parmesan cheese all surrounding lasagna and sitting on a white counter

Lasagna is considered a classic…and for good reason! It feeds a crowd, is wildly delicious, and is one of those dishes that tastes even BETTER the next day (and freezes like a dream!).

I, too, love a good lasagna and my veggie-loaded turkey lasagna or vegetarian lasagna soup are some of my regular go-tos when entertaining or when I need to bring a dish to someone else’s house (did I mention lasagnas travel easily also?!). As veggie-loading is my signature, of course I’ve played around with using different types of veggies as noodles and seeing where I can up the nutritional profile in other ways. And, while lasagna is amazing no matter how you slice it, I sometimes just crave a classic lasagna—regular noodles and all!

Now, what makes this easy vegetarian lasagna so much simpler to make than most? I’m glad you asked! It uses frozen spinach…. which means no chopping! And the noodles? I opted for oven ready noodles, so there is no boiling either. And, using your favorite jarred pasta sauce is a shortcut that gets dinner on the table fast! However, I do love keeping a stash of my easy homemade veggie-loaded pasta sauce on hand in the freezer so I can quickly defrost it and add it to this lasagna for even more veggie-loading with virtually no extra work!

I always try to balance convenience with maximum flavor payout in all of my veggie-loaded dinner recipes. After all, what good is a super fast recipe if it doesn’t make your tastebuds sing? This lasagna recipe strikes the perfect balance—using shortcuts without shortchanging texture and taste—and will have everyone at the table asking for seconds…or thirds!

This easy spinach lasagna is vegetarian, can easily be made gluten free with gluten free noodles, and is ideal for meal prep as it is fridge and freezer friendly! It also packs in a pound of frozen spinach and garnered high praise from my 12 year old daughter. She happily informed me that it was perfection! Her exact words. So…this is basically a unicorn dinner recipe(!) you’ll want to have in your back pocket for gatherings AND for the usual weeknight dinner rush….since it cooks up in about 40 minutes and makes 12 servings.

Ingredients for spinach lasagna on the table before being cooked together. — Ingredients: frozen chopped spinach, ricotta cheese, low fat or whole milk, shredded low-moisture mozzarella cheese, grated Parmesan cheese, garlic powder, Italian seasoning, kosher salt, ground black pepper, egg, pasta sauce, no-boil lasagna noodles

How to defrost your frozen spinach

Let the spinach defrost in the refrigerator overnight or microwave until defrosted. Place the spinach in a mesh strainer and use the back of a large spoon to press out and drain out extra water. Or, place defrosted spinach in a clean kitchen towel and squeeze the liquid out over the sink or bowl.

Pair of hands holding a spoon and a sieve. Spoon is pressing out water from defrosted (previously frozen) spinach in the colander. Sieve is resting on top of a glass bowl sitting on a counter. Bowl and sieve are surrounded by basil, a small plate of spices and a small plate of cheese set to the side of the image slightly out of frame.

How to make this spinach lasagna: a visual step-by-step guide

If you are a visual person, here is a picture guide for how this recipe should look at each step. Be sure to grab the exact measurements for the ingredients and helpful cooking tips by scrolling down to the recipe card below.

A glass bowl filled with spinach, ricotta, mozzarella cheese, parmesan, garlic powder, Italian seasoning, salt and pepper. There is also a white bowl filled with beaten egg and a fork in the bowl. Both bowls are sitting on a white counter. — In a large bowl add the spinach, ricotta, 1 cup grated mozzarella, parmesan, garlic powder, Italian seasoning, salt and pepper.

A glass bowl filled with spinach, ricotta, mozzarella cheese, parmesan, garlic powder, Italian seasoning, salt and pepper. A beaten egg is being poured from a small white bowl into the glass bowl filled with the other ingredients. — Add lightly beaten egg into the bowl with ricotta mixture ingredients.

A glass bowl filled with a ricotta mixture of spinach, ricotta, mozzarella cheese, parmesan, garlic powder, Italian seasoning, salt, pepper, and egg. Utensil is sitting in the mixture in the bowl. — Mix all ingredients together for ricotta mixture.

A white baking dish covered with a layer of marinara sauce at the bottom. — Spread 1 cup of the marinara sauce in the bottom of the baking dish.

A white baking dish with overlapping lasagna noodles (over a layer of marinara sauce). — Add an even layer of lasagna noodles. I use 6 for each layer. (It’s ok if they overlap slightly).

A hand holding a spoon is spreading the ricotta mixture over a layer of overlapping lasagna noodles (over a layer of marinara sauce) in a white baking dish. — Dollop half of the ricotta mixture over the noodles then spread into an even layer.

A hand holding a spoon is spreading marinara sauce over the ricotta mixture in a white baking dish. — Spoon 1 cup of marinara sauce over the ricotta layer and spread evenly.

A hand holding a spoon is spreading the ricotta mixture over a layer of overlapping lasagna noodles sitting on top of more layers of marinara sauce, ricotta mixture, and lasagna noodles. All ingredient are being assembled in a white baking dish. — Add another layer of noodles and then the remaining ricotta.

Cooked lasagna (with no cheese on top) in a white baking dish. — Place the final layer of noodles then spread the final cup of marinara sauce evenly over the top. Cover the dish with aluminum foil and bake until the noodles are tender, 40 to 45 minutes.

Shredded mozzarella cheese is sitting on top of cooked lasagna in a white baking dish. — Preheat the broiler. Remove the foil then sprinkle the remaining 1 ½ cups of mozzarella cheese evenly over the top. Broil until the cheese is golden brown, 1 to 2 minutes. (Watch closely to make sure the cheese doesn’t burn.)

Cooked lasagna with melted cheese on top in a white baking dish. — Allow the lasagna to set for 15 to 20 minutes before cutting into squares and serving. Store leftovers in the refrigerator for 3 days.

Suggested Adaptations + Tips

Lasagna noodles: If you want to use regular noodles instead of no-boil ones (including any gluten free varieties), simply soak the noodles in hot water for 20 minutes before using as instructed in the recipe. It adds more time to the prep, but beats having to run to the store before dinner!
To make a smaller batch of this lasagna, cut the recipe in half and bake in a 9-inch baking dish for 35 to 40 minutes.
Use your favorite pasta sauce. Personally, I feel like using a good pasta sauce really makes or breaks the flavor of a lasagna, so be sure you use one you love! I keep a stash of my easy homemade pasta sauce in the freezer to use in this recipe, but use whichever marinara sauce you like best!
Add meat. This spinach lasagna is naturally vegetarian, but you can up the protein by adding in cooked ground turkey or beef to the layers if you like!
Need egg free? The egg helps the ricotta mixture stay together a little more when you cut the lasagna. However, you can omit it if you need to and it won’t affect the flavor of the dish.

Cooked lasagna with melted cheese on top, cut into squares and sprinkled with basil in a white baking dish. More basil leaves, a serving utensil, and a napkin are set to the site of the image surrounding the baking dish with the lasagna.

How to store this easy spinach lasagna

Fridge: Once lasagna is cooked and cooled, you can tightly cover it or transfer slices to an air-tight container to store in the refrigerator for 3 days. Reheat slices in microwave or cover with foil and heat up in a 350℉ oven until warmed through.
Freezer: The lasagna can be assembled, wrapped in foil, and then frozen for up to 2 months. Before baking, defrost in the fridge for a full day and then bake. (It may take an extra 10 to 15 minutes if you put the lasagna in the oven when it’s cold.) You can bake the lasagna from frozen, but it will take up to an hour and a half to bake.

Other veggie-loaded lasagna and casserole recipes to try…

Did you try this spinach lasagna and now you’re hungry for more?

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