No-Noodle Sweet Potato Lasagna with Ricotta and Spinach

Layers of roasted sweet potato planks step in for pasta in this cozy weeknight lasagna. Ricotta, spinach, and mozzarella keep it creamy and substantial, while a good jar of marinara ties everything together fast.

The sweet potatoes get a quick roast first so they turn tender and a little caramelized on the edges. After that it is straight assembly, a hands-off bake, and ten minutes of patience while the lasagna sets up before you slice into it.

Why This One Stays in the Rotation

The sweet potato slices hold their shape but become almost velvety under the cheese and sauce. You get the comfort of a baked pasta with none of the boiling or timing fuss.

The filling is straightforward, no bechamel to whisk, and the whole thing can be assembled ahead. Leftovers are even better the next day because the flavors settle in and the slices cut cleanly.

Ingredients

• 3 medium sweet potatoes (about 2 lbs): look for long, straight ones that are easier to slice into even planks
• 2 tbsp olive oil
• 1 tsp kosher salt, divided
• 1/2 tsp black pepper, divided
• 10 oz frozen chopped spinach, thawed and squeezed dry completely
• 1 1/2 cups whole-milk ricotta
• 1 large egg
• 1 garlic clove, minced or pressed
• 1/2 tsp dried oregano
• 1/4 tsp red pepper flakes: (optional)
• 2 cups shredded low-moisture mozzarella, divided
• 1/2 cup grated Parmesan, divided
• 3 cups good-quality marinara sauce, divided

Variations / Substitutions

• Spinach swap: fresh baby spinach works, wilt 5 oz in a dry pan until just collapsed, then squeeze dry and chop.
• Add meat: brown 1/2 lb ground turkey or Italian sausage and stir it into the marinara before layering.
• Dairy-free option: use firm pressed tofu blended with a little lemon juice and salt in place of the ricotta, and your favorite dairy-free mozzarella shreds.
• Cheese swap: ricotta can be replaced with small-curd cottage cheese for a lighter, tangier filling.

If you like layered vegetable bakes, try Eggplant Parmesan next.

How to Make Sweet Potato Lasagna

Step 1: Roast the Sweet Potato Planks

Heat your oven to 400°F (200°C). Slice the sweet potatoes lengthwise into planks about 1/4 inch thick. Toss them with the 2 tbsp olive oil, 1/2 tsp of the salt, and 1/4 tsp of the pepper. Arrange in a single layer across two parchment-lined sheet pans, overlapping a little is fine but do not pile them up. Roast for 20 to 25 minutes, flipping once halfway, until the slices are tender at the center when poked with a fork. The edges should look slightly dry and just beginning to brown.

Let the roasted slices cool on the pans while you mix the filling. They don’t need to be cold, just cool enough to handle without tearing.

Step 2: Mix the Ricotta Filling

In a medium bowl, combine the drained spinach, ricotta, egg, minced garlic, the remaining 1/2 tsp salt, the remaining 1/4 tsp pepper, the oregano, and red pepper flakes if using. Stir until everything is evenly combined. It will look like a pale green, speckled mixture. Set aside.

Taste the filling now and adjust the salt if needed, keeping in mind that the Parmesan and marinara will also bring saltiness.

Step 3: Layer the Lasagna

Keep the oven at 400°F (200°C). Spread a thin layer of marinara (about 1/2 cup) across the bottom of a 9×13-inch baking dish. Lay half of the roasted sweet potato planks over the sauce in a single layer, it is okay if they overlap or have small gaps. Dollop half of the ricotta-spinach mixture over the sweet potatoes and spread it gently. Sprinkle with 1/3 of the mozzarella and 1/3 of the Parmesan. Pour 1 cup of marinara on top.

Repeat the layers: the remaining sweet potato planks, the rest of the ricotta mixture, another 1/3 of the mozzarella and Parmesan, and the remaining 1 1/2 cups marinara. Finish with the last 1/3 of the mozzarella and Parmesan scattered over the top.

Step 4: Bake Until Bubbly

Cover the dish tightly with foil and bake for 30 minutes. The foil traps steam and helps the sweet potato layers finish cooking without drying out. After 30 minutes, remove the foil and bake another 10 to 15 minutes, until the sauce is bubbling hard around the edges and the top cheese is melted and golden in spots. If you want a browner top, run the dish under the broiler for 1 to 2 minutes, keeping a close eye so it does not burn.

The kitchen will smell sweet and savory, and the edges of the sauce will look dark and sticky.

Step 5: Slice and Serve the Lasagna

Pull the dish out of the oven and let it sit on the counter for 10 to 15 minutes before you cut into it. This resting time is not optional, it lets the layers set so the slices hold together when you lift them out. Run a sharp knife around the edges, slice into 6 big squares, and lift out with a wide spatula. Garnish with fresh basil leaves if you have them and serve hot.

Tips for the Best Sweet Potato Lasagna

• The sweet potato thickness matters more than exact time. Use a mandoline or a sharp knife to get consistent 1/4-inch planks so they all tenderize at the same rate during roasting and baking.
• Squeeze the spinach as dry as you can to prevent a watery lasagna. Wrap it in a clean kitchen towel and wring out every last bit.
• Let the dish rest the full 10 to 15 minutes after baking. Cutting too soon will cause the whole thing to slide apart.
• Assemble the whole lasagna (unbaked) up to a day ahead, cover, and refrigerate. Add 5 to 10 extra minutes to the covered bake time when going straight from fridge to oven.

Roast times by sweet potato thickness:

Storing Leftovers

• Refrigerate: Cool completely, then cover and store in the fridge for up to 4 days. The squares firm up and slice even cleaner cold.
• Reheating: Warm individual portions in the microwave or cover the whole dish with foil and reheat at 350°F (175°C) until hot through, about 20 minutes.

What to Serve With Sweet Potato Lasagna

A crisp green salad with a sharp mustard vinaigrette cuts the richness without adding more work. Garlic bread or toasted ciabatta rubbed with butter and fresh garlic is good for sopping up the extra marinara. If you want more vegetables, roasted broccoli with lemon and a sprinkle of chili flakes sits right next to it on the plate.

Frequently Asked Questions

Can I use no-boil lasagna noodles instead of sweet potatoes?

Yes, you can turn this into a more traditional lasagna. Replace the sweet potato planks with one 9-ounce box of no-boil lasagna noodles and skip the roasting step entirely, assembling as written with three noodle layers instead of two.

How can I make this dairy-free?

Use firm tofu blended with lemon juice, nutritional yeast, and salt to mimic the ricotta, and choose a dairy-free mozzarella shred. The bake time stays the same.

Can I freeze this lasagna?

Absolutely. Assemble and bake it entirely, cool, then wrap the whole dish or individual portions tightly and freeze for up to 3 months. Thaw overnight in the fridge and reheat.

Why did my sweet potato layers turn out crunchy?

The slices were likely too thick or not roasted long enough in the first step. Next time aim for 1/4-inch thickness and roast until a fork slides in easily before layering.

Sweet Potato Lasagna Recipe

Print Recipe Pin Recipe

Prep Time 25 minutes mins

Cook Time 1 hour hr

Total Time 1 hour hr 25 minutes mins

Servings: 6 servings

Calories: 412

Ingredients Method Notes

Ingredients

  

• 3 medium sweet potatoes (about 2 lbs)
• 2 tbsp olive oil
• 1 tsp kosher salt
• 1/2 tsp black pepper
• 10 oz frozen chopped spinach, thawed and squeezed dry
• 1 1/2 cups whole-milk ricotta
• 1 large egg
• 1 garlic clove, minced
• 1/2 tsp dried oregano
• 1/4 tsp red pepper flakes (optional)
• 2 cups shredded low-moisture mozzarella
• 1/2 cup grated Parmesan
• 3 cups good-quality marinara sauce

Method

 

1. Heat oven to 400°F (200°C). Slice sweet potatoes lengthwise into 1/4-inch planks. Toss with olive oil, 1/2 tsp salt, and 1/4 tsp pepper. Roast in a single layer on two sheet pans for 20 to 25 minutes, flipping once, until tender.
2. Mix drained spinach, ricotta, egg, garlic, remaining salt and pepper, oregano, and red pepper flakes in a bowl until combined.
3. Spread 1/2 cup marinara in a 9×13-inch baking dish. Layer half the sweet potatoes, half the ricotta mixture, one-third each of mozzarella and Parmesan, and 1 cup marinara. Repeat layers, ending with the remaining cheese on top.
4. Cover with foil and bake 30 minutes. Remove foil and bake 10 to 15 minutes more until bubbling and golden.
5. Let the lasagna rest 10 to 15 minutes before slicing. Cut into squares and serve hot.

Notes

The rest after baking is important for clean slices. If the top is not as browned as you like, pop it under the broiler for a minute or two right before serving. Leftovers reheat beautifully and the sweet potato texture holds up.