Why You’ll Love Vegetarian Crockpot Lasagna Recipe

This slow cooker lasagna takes all the flavors you love about traditional lasagna and makes it easier — no boiling noodles ahead of time, and very little hands‑on work. The slow cooker does the heavy lifting while you go about your day, and dinner comes out hot, cheesy and delicious. Plus, it’s vegetarian, so it’s great for meatless meals that still feel satisfying.

Ingredients

(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)
1 ½ pounds baby bella mushrooms, roughly chopped
½ teaspoon salt
1 tablespoon olive oil
1 heaping cup onions, finely diced
2 large carrots, finely diced
24 ounces jar of spaghetti sauce, divided
15 ounce can of tomato sauce
2 (10‑ounce) boxes frozen chopped spinach, thawed and squeezed dry
15 ounces ricotta cheese (or vegan ricotta substitute)
1 teaspoon Italian seasoning
2 ½ cups shredded mozzarella cheese, divided (or vegan shredded cheese)
8–10 lasagna noodles

Directions

Spread about 2/3 cup of spaghetti sauce evenly in the bottom of your slow cooker and set it to high heat.
In a skillet over medium heat, cook the mushrooms with salt until they release their moisture and it mostly evaporates.
Add olive oil, onions and carrots to the skillet. Cook until carrots begin to soften, then stir in remaining spaghetti sauce and tomato sauce; remove from heat.
In a bowl, combine ricotta, 1 ½ cups of mozzarella, Italian seasoning and spinach.
Layer the lasagna in the slow cooker: place noodles over the sauce, add about one‑third of the ricotta mixture, then sauce, repeating until ingredients are used.
Cook on high for about 1 ½ hours.
Sprinkle the remaining mozzarella on top and cook for another 30 minutes until cheese is melted and bubbly.
Serve hot and enjoy!

Servings and timing

Servings: About 6 servings
Prep time: ~20 minutes
Cook time: ~2 hours
Total time: ~2 hours 20 minutes

Variations

• Use gluten‑free lasagna noodles to make this gluten‑free.
• Swap ricotta and mozzarella for vegan alternatives to make it fully vegan.
• Add layers of grilled zucchini or roasted bell peppers for extra veggies.
• Stir in fresh basil or oregano for a brighter herb flavor.

Storage/Reheating

• Storage: Refrigerate leftovers in an airtight container for up to 3–4 days.
• Freezing: You can freeze portions (without fresh cheese topping) for up to 2 months; thaw in the fridge before reheating.
• Reheating: Warm in the microwave or in an oven set to 175°C (350°F) until heated through.

FAQs

What slow cooker size should I use?

A 5–6 quart slow cooker works well for this lasagna to ensure even cooking and proper layering.

Do I need to pre‑cook the lasagna noodles?

No — the noodles cook in the sauces and liquids as the lasagna cooks in the crockpot.

Can I make this dairy‑free?

Yes — simply substitute ricotta and mozzarella with your favorite plant‑based cheeses.

How can I prevent the noodles from sticking together?

Ensure the sauce covers the noodles well and avoid overlapping too many noodles in one spot.

Can I add more vegetables?

Absolutely — spinach, zucchini, bell peppers or mushrooms all work great.

Is this recipe suitable for meal prep?

Yes — you can assemble it ahead of time and refrigerate before cooking.

Can I cook this on low instead of high?

Yes — cooking on low for 4–5 hours should yield similar results.

What can I serve with this lasagna?

A fresh green salad, garlic bread or roasted veggies make great side dishes.

How do I know when it’s done?

The lasagna is done when noodles are soft, cheese is melted, and edges bubble up slightly.

Can I use fresh spinach instead of frozen?

Yes — if using fresh spinach, sauté slightly first to reduce excess moisture.

Conclusion

This Vegetarian Crockpot Lasagna turns a classic favorite into a simple, hands‑off meal that’s perfect for busy days or relaxed weekends. With layers of cheesy goodness and hearty vegetables, it’s a satisfying dish that’s easy to customize and enjoy again and again.