Seafood Manicotti Alfredo with Shrimp and Crab

Manicotti shells are sturdy enough to hold a generous filling, but they can split when they’re cooked past al dente and then baked again. I learned to treat the first boil as a head start, not the finish line. That small distinction makes Seafood Manicotti Alfredo much easier to fill and keeps the shells intact under their blanket of cream sauce.

The filling brings ricotta, shrimp, and lump crab together with just enough egg and cheese to hold its shape. I make the Alfredo sauce separately, then spread some in the baking dish before adding the shells so the bottoms don’t dry out. After the covered bake, the mozzarella on top melts into the bubbling sauce, and the seafood stays tucked inside each tender shell.

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Kitchen Note

Chop the shrimp finely before mixing the filling, but leave the lump crab in bigger pieces. That contrast gives you a filling that’s easy to spoon into the shells without losing those tender bites of crab.

Save Seafood Manicotti Alfredo for a cozy dinner with creamy sauce, tender shells, and a shrimp-and-crab filling.

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Why Overcooking the Shells Makes the Filling Harder to Manage

Manicotti shells go through two rounds of cooking: the pot of boiling water and the oven. If they’re fully soft after the first round, they’re more likely to tear while you fill them and can turn fragile in the baking dish. Cooking them just until al dente gives them enough structure to handle the filling and enough room to finish softening in the sauce.

That brief rinse under cool water matters, too. It stops the shells from continuing to cook in their own heat and cools them enough to handle. Set them aside gently rather than piling them into a tight stack; a shell that sticks to its neighbor can split when you pull it apart.

The filling is rich, so the pasta doesn’t need to be cooked until completely tender in the pot. Let the covered bake do the finishing work. You’ll end up with shells that hold their shape instead of collapsing around the seafood.

Why Whole-Milk Ricotta and Heavy Cream Matter in This Alfredo

Seafood Manicotti Alfredo stuffed seafood pasta

Whole-milk ricotta — It gives the filling a creamy body that holds the shrimp and crab without making the mixture feel dry. Whole-milk ricotta is the right choice here; a leaner version can leave the filling less rich and less cohesive.
Egg — The egg helps the ricotta filling set as it bakes, so it stays inside the shells when you serve them. Keep it in the mixture rather than treating it as an optional binder.
Shrimp and lump crab — The cooked shrimp adds a firm, meaty bite, while lump crab brings softer flakes through the filling. Use shrimp that’s already peeled and deveined, and take a moment to check the crab for shell fragments.
Mozzarella and Parmesan — Mozzarella melts over the top and adds stretch to the filling. Parmesan brings a sharper, savory note to both the ricotta mixture and the sauce; finely grated cheese blends into the warm cream more smoothly than coarse shreds.
Heavy cream, butter, and garlic — Heavy cream gives this Alfredo its body, and butter carries the garlic through the sauce. Half-and-half doesn’t provide the same richness or thickness, so keep the heavy cream for a sauce that coats the shells instead of running thin.

From Al Dente Shells to a Bubbling Seafood Bake

Boil the Shells and Mix the Filling

Heat the oven to 375°F, then bring 4 quarts of water and 1 tablespoon of kosher salt to a boil. Cook the manicotti shells according to the package directions until just al dente, then drain, rinse under cool water, and set aside. In a large bowl, stir together the ricotta, egg, mozzarella, Parmesan, shrimp, crabmeat, and black pepper. Mix until the seafood is distributed through the cheese without crushing the crab into a paste.

Simmer the Cream Sauce Gently

Melt the butter in a medium saucepan over medium heat, then stir in the garlic and cook for 30 seconds, until fragrant. Add the heavy cream and bring it to a gentle simmer, stirring often as it cooks for 5 to 7 minutes. Watch for the cream to thicken slightly; a hard boil can make it reduce too quickly. Take the pan off the heat and stir in the Parmesan until the sauce is smooth.

Fill, Cover, and Bake

Spread about 1 cup of sauce across the bottom of a 9×13-inch baking dish. Spoon the seafood filling into the shells and arrange them in the dish, then pour the remaining sauce over the top and scatter on the remaining mozzarella. Cover the dish loosely with foil and bake for 20 minutes. Uncover and bake for another 10 to 15 minutes, until the sauce is bubbling and the center of the filling reaches 160°F. Rest the dish for 10 minutes before serving so the filling settles inside the shells.

Two Smart Changes Without Losing the Creamy Center

Use Gluten-Free Manicotti Shells

For a gluten-free version, use gluten-free manicotti shells and cook them according to their package directions until just al dente. They can be more delicate than wheat pasta, so handle them gently after draining; the seafood filling and Alfredo sauce stay the same.

Make the Filling Shrimp-Forward

Replace the crab with an equal amount of additional cooked shrimp. The filling will have a firmer, more uniform bite and lose the delicate sweetness that lump crab brings, while keeping the same ricotta-and-cheese base.

Storage and Reheating

Refrigerator: Refrigerate leftovers within 2 hours and eat them within 3 to 4 days. The pasta softens a little as it sits in the sauce.
Freezer: Freeze cooled portions in airtight containers for up to 2 to 3 months. Thaw them in the refrigerator overnight; the cream sauce may look slightly separated after thawing.
Reheating: Cover a portion and microwave it in short intervals until it reaches 165°F throughout. Avoid heating it for one long stretch, which can make the seafood tough and encourage the sauce to separate.

Questions That Come Up With Seafood Manicotti Alfredo

Can I assemble the manicotti the night before?+

Yes. Assemble the dish, cover it, and refrigerate it overnight. Because it will be cold going into the oven, allow extra baking time and use the bubbling sauce and the center of the filling to judge when it’s ready.

Can I use frozen cooked shrimp?+

Yes. Thaw the shrimp in the refrigerator, drain it well, and chop it before mixing the filling. Excess moisture can loosen the ricotta mixture and make the shells harder to fill.

Can I use canned lump crabmeat?+

Yes, canned lump crab works in the filling. Drain it well and pick through it for shell fragments before stirring it into the ricotta mixture.

Can I use half-and-half instead of heavy cream?+

I don’t recommend it. Half-and-half has less fat, so the Alfredo sauce will be thinner and won’t coat the manicotti as well; heavy cream gives it the body this baked dish needs.