Easy Spinach Lasagna
I started making this lasagna on an ordinary weeknight and realized it’s one of those recipes that quietly earns a permanent spot in the rotation. It feels special enough for guests but is straightforward enough to pull together without drama. Texturally, it balances a bright tomato sauce with velvety ricotta and plenty of spinach, and the mozzarella on top gives that familiar, comforting stretch we all want.
This version is forgiving. The steps are clear, the work spreads across a few stages that you can manage while the oven preheats, and it plays well with shortcuts like no‑boil noodles and frozen spinach. If you want to add protein, mild Italian sausage is optional and slots in easily.
Below you’ll find the exact ingredients and the step-by-step method I use, plus practical tips, common mistakes to avoid, and storage notes so every pan turns out reliably. Read through, prep your mise en place, and this will be one of the nicer dinners you make on a busy evening.
What Goes In
Ingredients
- 3 10-ounce packages frozen chopped spinach — the backbone of the filling and sauce; frozen saves time and keeps texture consistent.
- 2 tablespoons olive oil — for sautéing the onion and building the sauce base.
- 1 onion, finely chopped — adds sweetness and depth when softened; take your time to sweat it until soft.
- 5 garlic cloves, minced — fragrant lift in both sauce and filling; mince finely to distribute flavor.
- ⅛ teaspoon crushed red pepper flakes — just a whisper of heat to balance the tomatoes.
- 2 28-ounce cans crushed tomatoes — the sauce body; crushed gives texture without extra work.
- Kosher salt — seasons the tomato sauce and the ricotta mixture; taste as you go.
- Freshly ground black pepper — bright finish; add to sauce and filling per the recipe.
- 6 tablespoons chopped fresh basil, divided — fold half into the sauce and half into the ricotta for freshness throughout.
- 3 cups (24 ounces) ricotta — main component of the creamy filling; process for a smooth texture.
- 1 ½ cups grated Parmesan — salty, nutty backbone to the ricotta mixture.
- 2 large eggs — bind the ricotta filling so slices hold together.
- 12+ no-boil lasagna noodles — no pre-boil needed; they hydrate while baking with the sauce.
- 3 cups (12 ounces) shredded mozzarella — melty, gooey top and middle layers.
- 3-4 mild Italian sausage links, sliced and browned, optional for a non-vegetarian version — optional protein; slice and brown before assembling if you choose to use it.
Spinach Lasagna: From Prep to Plate
- Preheat oven to 375°F (190°C).
- If using the sausage, slice the links and brown them in a skillet over medium heat until cooked through; transfer to a plate and set aside.
- Place all three packages (3 × 10 oz) frozen chopped spinach in a large microwave-safe bowl and cover. Microwave until completely thawed, about 15 minutes, stirring once halfway through.
- After thawing, pour off and reserve 1/3 cup of the spinach liquid into a small measuring cup. Squeeze the thawed spinach dry with your hands or a towel to remove excess moisture.
- Transfer the squeezed spinach to a food processor and pulse 8–10 times, scraping down the bowl as needed, until the spinach is finely ground. Transfer the processed spinach to a clean bowl. Measure out 1/2 cup of the processed spinach and set it aside for the sauce; keep the remaining processed spinach in the bowl.
- Make the tomato-spinach sauce: heat 2 tablespoons olive oil in a large saucepan over medium heat until shimmering. Add the finely chopped onion and cook until softened, about 5 minutes. Stir in the minced garlic and 1/8 teaspoon crushed red pepper flakes and cook until fragrant, about 30 seconds. Add the two 28-ounce cans crushed tomatoes, the reserved 1/2 cup processed spinach, 1 teaspoon kosher salt, and 1/2 teaspoon freshly ground black pepper. Cook, stirring occasionally, until the sauce is slightly thickened, about 10 minutes. Remove from heat and stir in 3 tablespoons chopped fresh basil. Set the sauce aside.
- Make the ricotta-spinach filling: wipe out the food processor and add 3 cups (24 ounces) ricotta and the reserved 1/3 cup spinach liquid; process until smooth, about 30 seconds. Add 1 1/2 cups grated Parmesan, the remaining 3 tablespoons chopped fresh basil, 2 large eggs, 1 1/2 teaspoons kosher salt, and 1/2 teaspoon freshly ground black pepper; process until combined. Transfer this ricotta mixture into the bowl with the remaining processed spinach and stir until evenly combined.
- Assemble the lasagna in a 13×9-inch baking dish: spread 1 1/4 cups of the sauce evenly over the bottom of the dish. Arrange 3 no‑boil lasagna noodles in a single layer over the sauce. Spread one-third of the ricotta-spinach mixture evenly over the noodles. Sprinkle 2/3 cup shredded mozzarella over the ricotta. Spoon 1 1/4 cups of sauce over the mozzarella and, if using sausage, scatter some of the browned sausage pieces over this sauce.
- Repeat the layer described in step 8 two more times: for each repetition place 3 noodles, spread the next one-third of the ricotta-spinach mixture, sprinkle 2/3 cup mozzarella, and top with 1 1/4 cups sauce (and more sausage if using). This creates three stacked noodle/filling layers.
- Finish the top: arrange the remaining 3 noodles over the last sauce, spoon the remaining sauce evenly over the top noodles, and sprinkle with the remaining 1 cup shredded mozzarella.
- Cover the pan tightly with aluminum foil and bake until bubbling around the edges, about 40 minutes. Remove the foil and bake until the cheese is melted and lightly browned, about 10 more minutes. Remove from the oven and cool on a wire rack for 30 minutes before slicing and serving.
Why You’ll Keep Making It
This lasagna balances ease and flavor. Using frozen spinach and no‑boil noodles keeps prep short without sacrificing texture. The two-way spinach approach—some folded into the sauce, the rest in the ricotta—means the vegetable flavor is integrated rather than isolated. That makes every forkful familiar but layered.
The recipe scales well. It feeds a crowd, freezes nicely, and reheats cleanly. If you want to meal-prep, bake the lasagna, cool, portion, and freeze individual slices. The components are forgiving: the sauce tolerates a little extra simmering and the ricotta filling holds its shape once chilled.
Swap Guide
- Skip the optional sausage — make it fully vegetarian by leaving it out; the dish will still be hearty.
- Adjust the heat — the recipe uses ⅛ teaspoon crushed red pepper flakes; increase slightly if you want more warmth or omit if serving kids.
- More basil — the recipe uses 6 tablespoons fresh basil total; if you love basil, stir additional chopped leaves into the finished slices as a fresh finish.
Equipment Breakdown
- 13×9-inch baking dish — the assembly and bake space called for in the recipe.
- Food processor — used twice: to finely grind spinach and to smooth the ricotta mixture; it makes texture consistent and assembly faster.
- Large saucepan — for the tomato-spinach sauce.
- Skillet — for browning optional sausage.
- Large microwave-safe bowl — to thaw frozen spinach quickly and evenly.
- Mixing bowls, measuring cups, and a wire rack — for cooling the lasagna before slicing.
- Aluminum foil — cover the pan while baking to keep moisture in.
What Not to Do
- Don’t skip squeezing the spinach dry. Excess water thins the ricotta filling and can make the lasagna watery.
- Don’t undercook the onion. A faintly crunchy onion jumps out of the sauce; soften it until translucent for the best depth.
- Don’t remove the foil too early. The covered bake lets the noodles hydrate; pulling it off too soon can dry the top layers.
- Don’t skip the 30-minute resting time. The lasagna firms up while cooling and slices cleanly after resting.
Seasonal Flavor Boosts
- Summer — stir extra chopped fresh basil into warm slices right before serving for a bright, herb-forward finish.
- Fall/Winter — increase the crushed red pepper flakes slightly for a cozier, spicier edge if you like heat with tomato-rich dishes.
- Anytime — a light drizzle of good olive oil over each slice slices before plating gives a glossy, restaurant-style finish.
Method to the Madness
This recipe separates the spinach into two roles on purpose. Holding back 1/2 cup of processed spinach for the sauce keeps the tomato base from tasting strictly like tomato; it melds the filling and sauce. Processing the rest of the spinach and blending it into ricotta yields a smoother, greener filling that spreads evenly over the noodles.
Reserving and using 1/3 cup of the spinach liquid in the ricotta is a small trick that adds moisture and a hint of spinach flavor without additional chopping. Processing the ricotta with that liquid ensures a silky texture and helps the eggs and cheese bind the filling for clean slices.
Store, Freeze & Reheat
Store
Cover leftover lasagna tightly and refrigerate for up to 4 days. Keep slices in an airtight container to prevent the noodles from drying out.
Freeze
Freeze either the whole pan or individual slices. Wrap tightly in plastic wrap and then foil, or use freezer-safe containers. Freeze for up to 3 months. Thaw overnight in the fridge before reheating.
Reheat
To reheat a slice: place it in a baking dish, cover with foil, and bake at 350°F (175°C) until heated through, about 20–30 minutes depending on thickness. For single slices, a microwave works in a pinch—cover and heat in 45–60 second increments until warmed—but the oven keeps the texture best.
Reader Questions
- Q: Can I use fresh spinach?
A: Yes, but fresh spinach must be cooked down and well-drained before processing. Use enough cooked spinach so you still have the volume the recipe implies; be mindful that fresh will cook down dramatically. - Q: Can I make this ahead?
A: Assemble the lasagna and refrigerate (covered) for up to 24 hours before baking. Add 10–15 minutes to the covered baking time if baking directly from chilled. - Q: How do I know when it’s done?
A: It will be bubbling around the edges when covered and the top cheese should be melted and lightly browned after you remove the foil.
Time to Try It
Make a list, pull out the food processor, and set a 30-minute window for cooling at the end. The most time-intensive parts are unattended: thawing the spinach and the baking. Prep work is repetitive but straightforward. Follow the steps, don’t rush the squeeze-and-process stage, and you’ll have a lasagna that looks impressive and delivers comforting, reliable flavor.
Come back and tell me how it went—did you add sausage or keep it vegetarian? Did you find any shortcuts that worked? I’m always swapping notes and love tweaks that make a busy weeknight better.
Easy Spinach Lasagna
Ingredients
Ingredients
- 3 10- ounce packages frozen chopped spinach
- 2 tablespoons olive oil
- 1 onion finely chopped
- 5 garlic cloves minced
- 1/8 teaspoon crushed red pepper flakes
- 2 28- ounce cans crushed tomatoes
- Kosher salt
- Freshly ground black pepper
- 6 tablespoons chopped fresh basil divided
- 3 cups 24 ounces ricotta
- 1 1/2 cups grated Parmesan
- 2 large eggs
- 12 + no-boil lasagna noodles
- 3 cups 12 ounces shredded mozzarella
- 3-4 mild Italian sausage links sliced and browned, optional for a non-vegetarian version
Instructions
Instructions
- Preheat oven to 375°F (190°C).
- If using the sausage, slice the links and brown them in a skillet over medium heat until cooked through; transfer to a plate and set aside.
- Place all three packages (3 × 10 oz) frozen chopped spinach in a large microwave-safe bowl and cover. Microwave until completely thawed, about 15 minutes, stirring once halfway through.
- After thawing, pour off and reserve 1/3 cup of the spinach liquid into a small measuring cup. Squeeze the thawed spinach dry with your hands or a towel to remove excess moisture.
- Transfer the squeezed spinach to a food processor and pulse 8–10 times, scraping down the bowl as needed, until the spinach is finely ground. Transfer the processed spinach to a clean bowl. Measure out 1/2 cup of the processed spinach and set it aside for the sauce; keep the remaining processed spinach in the bowl.
- Make the tomato-spinach sauce: heat 2 tablespoons olive oil in a large saucepan over medium heat until shimmering. Add the finely chopped onion and cook until softened, about 5 minutes. Stir in the minced garlic and 1/8 teaspoon crushed red pepper flakes and cook until fragrant, about 30 seconds. Add the two 28-ounce cans crushed tomatoes, the reserved 1/2 cup processed spinach, 1 teaspoon kosher salt, and 1/2 teaspoon freshly ground black pepper. Cook, stirring occasionally, until the sauce is slightly thickened, about 10 minutes. Remove from heat and stir in 3 tablespoons chopped fresh basil. Set the sauce aside.
- Make the ricotta-spinach filling: wipe out the food processor and add 3 cups (24 ounces) ricotta and the reserved 1/3 cup spinach liquid; process until smooth, about 30 seconds. Add 1 1/2 cups grated Parmesan, the remaining 3 tablespoons chopped fresh basil, 2 large eggs, 1 1/2 teaspoons kosher salt, and 1/2 teaspoon freshly ground black pepper; process until combined. Transfer this ricotta mixture into the bowl with the remaining processed spinach and stir until evenly combined.
- Assemble the lasagna in a 13x9-inch baking dish: spread 1 1/4 cups of the sauce evenly over the bottom of the dish. Arrange 3 no‑boil lasagna noodles in a single layer over the sauce. Spread one-third of the ricotta-spinach mixture evenly over the noodles. Sprinkle 2/3 cup shredded mozzarella over the ricotta. Spoon 1 1/4 cups of sauce over the mozzarella and, if using sausage, scatter some of the browned sausage pieces over this sauce.
- Repeat the layer described in step 8 two more times: for each repetition place 3 noodles, spread the next one-third of the ricotta-spinach mixture, sprinkle 2/3 cup mozzarella, and top with 1 1/4 cups sauce (and more sausage if using). This creates three stacked noodle/filling layers.
- Finish the top: arrange the remaining 3 noodles over the last sauce, spoon the remaining sauce evenly over the top noodles, and sprinkle with the remaining 1 cup shredded mozzarella.
- Cover the pan tightly with aluminum foil and bake until bubbling around the edges, about 40 minutes. Remove the foil and bake until the cheese is melted and lightly browned, about 10 more minutes. Remove from the oven and cool on a wire rack for 30 minutes before slicing and serving.
Equipment
- Oven
- Skillet
- Microwave-safe bowl
- Measuring cup
- Kitchen Towel
- Food Processor
- Large Saucepan
- 13x9-inch baking dish
- Aluminum Foil
- Wire Rack
