Stuffed Shells with Spinach and Ricotta (Creamy and Cheesy)

Stuffed shells are the kind of dinner that looks like a project but really is not. Jumbo pasta shells get filled with a creamy ricotta and spinach mixture, tucked into a dish of marinara and baked under a blanket of melted mozzarella.

The filling comes together in one bowl in about five minutes. The shells boil while you mix it. After that, it is just spooning, arranging and baking, and the oven does the rest.

This version leans on whole milk ricotta, a generous amount of Parmesan and well drained spinach, so the filling stays rich and creamy instead of watery. It feeds six comfortably and reheats beautifully the next day.

Why this recipe works

• Whole milk ricotta. Full fat ricotta gives you a filling that bakes up creamy instead of grainy or dry.
• Spinach squeezed dry. Wringing every bit of water out of the thawed spinach is the single most important step. It keeps the filling thick and the sauce from turning soupy.
• One egg for structure. A single egg binds the filling so each shell holds its shape when you cut into it.
• Shells cooked just shy of done. Boiling the shells for two minutes less than the package says keeps them from tearing while you fill them, and they finish cooking in the sauce.
• Sauce above and below. A layer of marinara under the shells and a spoonful over each one keeps everything moist during baking.
• Covered, then uncovered. Baking under foil first heats the filling through gently. Uncovering at the end browns the cheese without drying out the pasta.

Ingredients you’ll need

The full list with amounts is in the recipe card. Here is what matters about the main ingredients.

• Jumbo pasta shells. A 12 oz box holds about 30 shells. You will fill 24, and the extras cover any that tear during boiling.
• Whole milk ricotta. One 15 oz container is the base of the filling. Skim ricotta works in a pinch but bakes up drier.
• Frozen chopped spinach. A 10 oz box, thawed and squeezed until it feels almost dry. Frozen spinach is easier and more consistent here than fresh.
• Mozzarella and Parmesan. Mozzarella melts into that stretchy top layer. Parmesan brings salt and a sharp, nutty depth to the filling.
• One large egg. It binds the filling so it does not slump out of the shells.
• Garlic, nutmeg, salt and pepper. Fresh garlic and a small pinch of nutmeg make a ricotta filling taste like something from a good Italian restaurant.
• Marinara sauce. One 24 oz jar or 3 cups of homemade. Pick a sauce you like eating on its own, because it is a big part of the final flavor.

Ingredient notes and smart substitutions

Ricotta

Whole milk ricotta is the best choice. If yours seems very wet, spoon it into a fine mesh strainer over a bowl for 20 to 30 minutes before mixing.

To swap, use 15 oz of small curd cottage cheese, drained and blended smooth in a food processor. It gives a similar texture with a slightly tangier flavor.

Spinach

Frozen chopped spinach is the easy route. For fresh, cook 1 lb of baby spinach in a dry skillet until wilted, cool it, then chop and squeeze it dry. That yields about 1 cup, the same as one 10 oz frozen box.

Frozen kale or chopped Swiss chard can stand in at the same amount. Both need the same thorough squeeze.

Mozzarella

Low moisture mozzarella, shredded from a block, melts best and browns nicely. Bagged shredded mozzarella is fine but melts a little less smoothly because of the anti caking starch.

Fresh mozzarella releases too much water for this dish. If it is all you have, tear it into small pieces and use half the amount on top only.

Parmesan

Grate a wedge yourself if you can. Pecorino Romano is a sharper, saltier swap at a one to one ratio. If you use Pecorino, cut the salt in the filling to 3/4 teaspoon.

Marinara

Any good jarred marinara works, and a tomato basil sauce is a nice match. To make a quick sauce, simmer one 28 oz can of crushed tomatoes with 2 tablespoons olive oil, 2 minced garlic cloves and 1/2 teaspoon salt for 15 minutes.

For a richer dish, replace 1 cup of the marinara with 1 cup of vodka sauce or a meat sauce.

How to make it

1. Boil the shells

Bring a large pot of well salted water to a boil. Add the shells and cook for 2 minutes less than the package directions, usually about 9 minutes, stirring gently at the start so they do not stick together.

Drain and lay the shells out in a single layer on a baking sheet so they cool without sticking. Do not rinse them. The little bit of starch on the surface helps the sauce cling.

2. Squeeze the spinach

Put the thawed spinach in a clean kitchen towel or a few layers of paper towels and twist hard over the sink. Keep going until almost no liquid comes out. You should end up with a compact ball about the size of a baseball.

3. Mix the filling

In a large bowl, stir together the ricotta, spinach, 1 cup of the mozzarella, the Parmesan, egg, garlic, nutmeg, salt and pepper. Mix until evenly combined but do not beat it, which can make the ricotta loose.

Taste a tiny bit before the egg goes in if you want to adjust salt. Once the egg is in, trust the seasoning.

4. Sauce the dish

Heat the oven to 375°F. Spread 1 1/2 cups of the marinara over the bottom of a 9 by 13 inch baking dish. This layer keeps the shells from sticking and drying out.

5. Fill the shells

Spoon about 2 tablespoons of filling into each shell. A small cookie scoop or a zip top bag with a corner snipped off makes this fast. Nestle the shells open side up in the dish in rows. They can touch but should not be stacked.

6. Top and bake

Spoon the remaining marinara over the shells, then scatter the last 1/2 cup of mozzarella on top. Cover the dish tightly with foil and bake for 25 minutes.

Remove the foil and bake for 10 to 15 minutes more, until the sauce bubbles at the edges and the cheese is melted with a few golden spots. Let it rest for 5 minutes before serving so the filling sets.

Common mistakes and how to fix them

Watery filling. This almost always comes from spinach that was not squeezed enough or from very wet ricotta. Squeeze harder, and strain the ricotta if it looks loose in the container.

Torn shells. Overcooked shells split when you fill them. Pull them from the water while they still have a little firmness. Cook the whole box so you have spares.

Dry, chewy pasta edges. Shells that peek out above the sauce turn leathery in the oven. Make sure each one gets a spoonful of sauce on top and keep the dish covered for the first stretch of baking.

Bland filling. Ricotta needs real seasoning. Do not skip the salt, garlic or Parmesan, and add the nutmeg even if it sounds odd. It makes the cheese taste rounder.

Cheese burned before the center is hot. If the top is browning too fast, tent the foil loosely back over the dish for the last few minutes.

Timing and make ahead plan

From start to table, plan on about 75 minutes. Roughly 30 minutes of that is hands on time for boiling, mixing and filling, and the rest is oven time.

To get ahead, assemble the whole dish up to 24 hours in advance. Cover and refrigerate, then add about 10 minutes to the covered baking time since it starts cold.

You can also make the filling alone up to 2 days ahead and keep it covered in the refrigerator. Boil and fill the shells the day you bake.

For a freezer meal, assemble the shells in a foil pan without the top layer of cheese, wrap tightly and freeze for up to 3 months. Bake from frozen, covered, at 375°F for about 60 minutes, then uncover, add the cheese and bake 15 minutes more.

Tips for the best stuffed shells

Salt the pasta water generously. The shells are the only part of the dish that gets seasoned from the outside, and underseasoned pasta makes the whole thing taste flat.

Use a piping bag or zip top bag for the filling. It is neater than a spoon and gets the shells fully packed without tearing them.

Leave a little room between the shells and the edge of the dish so sauce can bubble up around them. A dish that is packed too tightly steams instead of bakes.

Let the dish rest for at least 5 minutes after baking. The filling firms up slightly and the shells hold together when you lift them out.

Finish with fresh basil or a drizzle of good olive oil at the table. It brightens the rich cheese and tomato flavors.

Variations

Meat sauce shells. Brown 1/2 lb of Italian sausage or ground beef to 160°F, drain, and stir it into the marinara before saucing the dish.

Three cheese shells. Skip the spinach and add an extra 1/2 cup of shredded provolone or fontina to the filling for a richer, cheese forward version.

Mushroom shells. Sauté 8 oz of finely chopped mushrooms in butter until browned and dry, then fold them into the filling with or instead of the spinach.

Alfredo topped shells. Replace half the marinara with a cup of creamy Alfredo sauce for a pink sauce effect. It pairs well with the spinach filling.

Spicy shells. Add 1/2 teaspoon of red pepper flakes to the filling and use a spicy arrabbiata sauce in place of plain marinara.

Equipment that makes this easier

A large pot, at least 6 quarts, gives the shells room to move so they cook evenly without sticking. A 9 by 13 inch baking dish holds 24 shells in a single layer with room for sauce.

A fine mesh strainer helps if your ricotta is wet. A small cookie scoop or a disposable piping bag makes filling quick and tidy.

Heavy duty foil is worth having for the covered stage of baking. Thin foil tends to tear and lift when it touches the sauce.

Scaling up or down

To halve the recipe, use 12 shells, a 7 by 11 inch or 8 by 8 inch dish and half of every filling ingredient. The egg is the tricky part. Beat one egg, then use about 2 tablespoons of it. Baking time stays about the same.

To double, make two 9 by 13 inch pans rather than one overloaded dish. Two pans side by side on the same rack bake in the same time, though you may need an extra 5 minutes uncovered.

The filling scales easily, so mixing a double batch and freezing half for later is a smart move.

What to serve with it

Stuffed shells are rich, so keep the sides simple. A crisp green salad with a sharp vinaigrette and a loaf of warm garlic bread are the classic pairing.

For a bigger Italian spread, start with a bowl of Italian wedding soup or serve the shells alongside a pan of baked ziti for a crowd.

Roasted broccoli, sautéed green beans or any of these fall side dishes round out the plate without competing with the pasta.

If you love this style of cooking, a classic meat lasagna uses the same ricotta filling ideas in layered form.

How to store, freeze and reheat

Refrigerator. Cool leftovers, cover and refrigerate for up to 4 days.

Freezer. Freeze baked shells in an airtight container for up to 3 months. Wrap individual portions for easy lunches.

Reheating. Warm single portions in the microwave with a spoonful of extra sauce or a splash of water, covered, until steaming hot. For a full dish, cover with foil and bake at 350°F for 25 to 30 minutes, until the center reaches 165°F.

Thaw frozen portions overnight in the refrigerator for the best texture, or reheat from frozen at a lower power setting, stirring the sauce around them as they warm.

Leftover ideas

Chop leftover shells roughly and bake them with a little extra sauce and cheese in a small dish for a quick pasta bake.

Slice a cold shell in half and tuck it into a crusty roll with extra marinara for a stuffed shell sandwich that reheats well in a toaster oven.

Turn two leftover shells into lunch by setting them on a bed of baby spinach. The warm sauce wilts the greens just enough.

Nutrition notes

One serving of four shells with sauce and cheese lands roughly in the range of 450 to 550 calories, with about 25 grams of protein and 20 to 25 grams of fat. Numbers vary with the ricotta, the brand of marinara and how much mozzarella you add on top.

To lighten it, use part skim ricotta and mozzarella and reduce the cheese on top by half. To add fiber, stir extra spinach into the filling or serve a large salad alongside.

Frequently asked questions

Do you have to cook jumbo shells before stuffing them?

Yes, for this recipe. Boil them 2 minutes short of the package time so they are pliable but firm enough to fill without tearing. They finish cooking in the sauce.

How do you keep stuffed shells from being watery?

Squeeze the thawed spinach until it is nearly dry and use whole milk ricotta. If the ricotta looks wet, drain it in a fine mesh strainer for 20 to 30 minutes first.

Can I make stuffed shells ahead of time?

Yes. Assemble the dish up to a day ahead, cover and refrigerate, then bake with about 10 extra minutes under the foil. You can also freeze the assembled dish for up to 3 months.

Can I use cottage cheese instead of ricotta?

Yes. Drain 15 oz of small curd cottage cheese and blend it smooth in a food processor. It gives a similar creamy texture with a slightly tangier taste.

How many stuffed shells per person?

Plan on 4 shells per adult as a main course with a salad or bread. A 12 oz box fills 24 shells, which serves 6.