This is a softer, creamier take on a classic lasagna, with layers that cook slowly into a rich, comforting dish. I love these flavours together, I think you will too!
It’s simple to put together, with a few key steps to help the layers cook evenly and slice nicely.
Getting the spinach right so your lasagna isn’t watery
I use frozen spinach here, so much easier to use. But not all frozen spinach is created equally, and some can have quite an odd taste. I find that chopped or cut leaf frozen spinach is better than that which comes in little bricks, where it is very fine and not as good quality. Fresh spinach is easier to use, but still chop it finely so it blends through the filling rather than sitting in pockets and you will need a lot of fresh spinach.
The main thing to watch with slow cooker lasagna is moisture. There’s very little evaporation, so any extra liquid stays in the dish.
If you’re using frozen spinach, it must be thoroughly drained. After thawing, squeeze it firmly in your hands or press it through a sieve until no more liquid runs out. Even a little extra water will loosen the ricotta mixture and stop the layers setting properly.
Building a ricotta filling that stays creamy
Mix the ricotta and cream cheese until it’s really smooth before adding anything else. This step helps avoid a grainy finish and ensures the filling spreads easily across the pasta layers.
The egg helps it set, while the cream cheese keeps it rich and smooth so it holds together without feeling heavy.
Sauce consistency matters more than you think
The tomato sauce should be a little looser than a stovetop version so the pasta can soften properly as it cooks.
Cooking the tomato paste with the herbs first deepens the flavour and takes away that raw taste. Once the liquids are added, a short simmer is enough to bring everything together.
If the sauce is too thick, the pasta can struggle to soften. If it’s too thin, the layers won’t hold as well. You’re looking for a sauce that pours easily but still has a bit of body.
Layering so everything cooks evenly
Break the noodles (pasta sheets) to fit so you get an even layer without too much overlap. Spreading the ricotta mixture in a thin, consistent layer helps avoid dense spots and keeps the texture even throughout. I dollop the ricotta on then spread it out.
Make sure each layer of pasta is fully covered with sauce so it cooks evenly. Finish with a full layer of sauce on top so the pasta doesn’t dry out as it cooks.
Timing and how to tell when it’s ready
Cooking on LOW helps the pasta soften gently without overcooking the edges. To check, slide a knife into the centre, it should slide in easily.
Add the cheese at the end so it melts nicely without overcooking. If you prefer a golden cheesy top, you can finish it briefly under the broiler/grill if your slow cooker insert can go in the oven.
Let it rest for about 20 minutes before serving so the layers settle and it slices more neatly.
How to Make Slow Cooker Spinach & Ricotta Lasagna
Step 1. Prepare and simmer the tomato sauce until it comes together and thickens slightly and set aside. I also get the cream cheese out from the fridge at this time to soften.
Step 2. Heat the spinach gently in the microwave, then squeeze all of the liquid from the spinach. Beat the ricotta and cream cheese until smooth, then mix in remaining filling ingredients
Step 3. In your slow cooker bowl, layer the sauce, pasta and ricotta mixture then repeat.
Step 4. Repeat layers, finishing with pasta and sauce.
Step 5. Cook on LOW until the pasta is tender, then add the cheese, let it melt, (I like to then pop mine in the oven on broiler or grill to become golden and bubble. Then rest before serving.
What to know before you start this recipe
Can I use no-boil lasagna noodles/pasta sheets?
Yes, but they tend to soften more. Regular noodles/pasta sheets hold their structure better in the slow cooker.
Do I need to cook the pasta first?
No, they cook directly in the sauce as the lasagna cooks.
Can I skip sautéing the onions and garlic?
You can, but the flavour will be lighter. Cooking them first adds depth to the sauce.
Can I make this ahead of time?
Yes. Assemble the lasagna, refrigerate it, then cook when you’re ready.
If you enjoy this style of slow cooker meal, you might also like:
- Slow Cooker Creamy Vegetable Alfredo
- Slow Cooker Mushroom Risotto
- Slow Cooker Pumpkin & Chickpea Curry
- Lentil & Vegetable Cottage Pie
You can find more easy and hearty meat-free recipes in my Easy Slow Cooker Vegetarian Meals collection.
If you make this, I’d love you to rate it in the recipe card below
Slow Cooker Spinach & Ricotta Lasagna
A creamy slow cooker spinach and ricotta lasagna with soft layers, rich tomato sauce, and a smooth, sliceable finish.
Ingredients
Tomato Sauce
- 2 tablespoons olive oil
- 1 small onion, finely diced
- 4 cloves garlic, crushed
- 1 tablespoon tomato paste
- 1 teaspoon dried oregano
- ½ teaspoon dried basil
- 1 tablespoon Worcestershire sauce (vegan if required)
- 700 g tomato passata or pasta sauce (24.7 oz)
- 400 g tin crushed tomatoes (14 oz can)
- ¾ cup vegetable stock or water (185 ml / 6.3 fl oz)
- ½ teaspoon salt
- ¼ teaspoon black pepper
- ½ teaspoon brown sugar
Spinach & Ricotta Filling
- 500 g ricotta (1.1 lb)
- 125 g cream cheese, softened (4.4 oz)
- 1 large egg
- ¾ cup finely grated parmesan (about 75 g / 2.6 oz)
- 300 g spinach (fresh spinach cooked and squeezed dry, or frozen loose-leaf spinach, thawed and squeezed very dry) (10.6 oz)
- ½ teaspoon lemon zest
- ¼ teaspoon nutmeg
- ½ teaspoon salt
- ¼ teaspoon black pepper
To Assemble
- 9–12 dried lasagne sheets or noodles (regular, not pre-soaked)
- 1½ cups grated mozzarella (375 ml / 12.7 fl oz)
- ¼ cup grated parmesan (60 ml / 2 fl oz)
Instructions
- If using frozen spinach, place it in a microwave-safe bowl and microwave for 2–3 minutes, stirring once if possible. Transfer to a sieve or colander. When cool enough to handle, press or squeeze out all the liquid, then set aside to drain further.
- Remove the cream cheese and ricotta from the fridge now, to begin to soften.
- Heat the olive oil in a large frying pan over medium heat. Add the onion and cook for 4–5 minutes until softened. Stir in the garlic and cook for another minute until fragrant.
- Add the tomato paste, oregano and basil and cook for 1–2 minutes, stirring, so the tomato paste darkens slightly and the herbs release their flavor.
- Stir in the passata, crushed tomatoes, vegetable stock, Worcestershire sauce, salt, pepper and brown sugar. Simmer gently for 5 minutes until the sauce is well combined and slightly thickened. Remove from the heat.
- In a large bowl add the ricotta and cream cheese and beat well with a wooden spoon until creamy for at least 60 seconds. Then add the egg. Mix until smooth. Stir through the first measure of Parmesan, spinach, lemon zest, nutmeg, salt and pepper until evenly combined.
- Spoon about 1 to 1½ cups of the tomato sauce over the base of the slow cooker and spread it out evenly.
- Break lasagna noodles to fit and arrange a single layer over the sauce.
- Dollop one third of the spinach ricotta mixture in tablespoon-sized heaps over the pasta, then spread it in a thin even layer across the pasta.
- Pour over 1 cup of the tomato sauce and spread well.
- Repeat the layers of pasta, ricotta mixture and sauce two more times, finishing with a layer of pasta topped with the remaining tomato sauce.
- Place the lid on and cook on LOW for 3½–4 hours, or until the pasta is tender when pierced with a knife.
- Sprinkle the mozzarella and Parmesan over the top. Replace the lid slightly ajar if possible and cook for a further 10–15 minutes until the cheese has melted.
- If you wish for a golden brown top, place an oven-proof slow cooker insert in the oven under the broil setting until golden and bubbling.
- Turn off the slow cooker and allow the lasagna to rest for 15–20 minutes before serving so the layers can settle and slice neatly.
- Serve warm, sliced into portions once the lasagna has rested and set
- Allow leftovers to cool completely, then cover or transfer to an airtight container. Store in the refrigerator for up to 3 days.
- This lasagna freezes well either whole or in portions.
- Cool completely, then wrap tightly or store in freezer-safe containers for up to 3 months.
- Reheat portions in the microwave until heated through, or cover and warm in the oven at 325°F (160°C) until hot in the center.
- If reheating from frozen, thaw overnight in the refrigerator for best results.
Notes
• Make sure the spinach is squeezed very dry so it doesn’t water down the filling.
• The sauce should be slightly looser than a normal pasta sauce so the pasta can soften as it cooks.
• Three pasta layers is ideal for slow cooker lasagne so the centre cooks evenly.
Nutrition Information:
Yield: 6 Serving Size: 1Amount Per Serving: Calories: 26648Total Fat: 1322gSaturated Fat: 666gUnsaturated Fat: 656gCholesterol: 4204mgSodium: 96857mgCarbohydrates: 2362gFiber: 457gSugar: 1168gProtein: 1605g
This nutrition calculation for Just Slow Cooker Recipes has been automated, please use your discretion with the calculation and use your own if unsure.
Thank you so much for stopping by to check out this recipe and the others here on my blog. I always love sharing these slow cooker favourites with you.
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Happy cooking!
Anna xo
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