This 4-ingredient slow cooker stuffed manicotti is one of those set-it-and-forget-it meals that feels way fancier than the effort it takes. You literally toss frozen manicotti tubes into your crockpot, pour over a few pantry staples, and let the slow cooker do the work. It’s perfect for busy weeknights, potlucks, or a casual cookout when you want something comforting and crowd-pleasing without babysitting the oven. No boiling pasta, no mixing fillings—just simple ingredients that turn into a cheesy, saucy, stick-to-your-ribs dinner everyone will be talking about.
Serve these slow cooker manicotti straight from the warm crock with a big green salad, garlic bread, or buttered Texas toast to soak up the extra sauce. At a cookout, I like to set the slow cooker on the buffet table, keep it on warm, and let folks scoop their own alongside grilled veggies, corn on the cob, or a crisp coleslaw. A sprinkle of extra Parmesan and some fresh basil or parsley on top makes it feel restaurant-worthy with almost no extra effort.
4-Ingredient Slow Cooker Stuffed Manicotti
Servings: 6

Ingredients
1 (24–26 oz) jar marinara or pasta sauce
1/2 cup water
1 (22–24 oz) bag frozen cheese-stuffed manicotti tubes
2 cups shredded mozzarella cheese, divided
Directions
Spray the inside of a 5- to 6-quart slow cooker with nonstick cooking spray to help prevent sticking and make cleanup easier.
In a medium bowl or large measuring cup, stir together the marinara or pasta sauce and the water until evenly combined. This extra liquid keeps the frozen manicotti from drying out while they cook.
Spread about 1/2 cup of the thinned sauce in an even layer over the bottom of the slow cooker. This should just lightly coat the ceramic insert so the manicotti don’t stick.
Place the frozen cheese-stuffed manicotti tubes in a single snug layer over the sauce in the bottom of the slow cooker. It’s okay if they touch, but try to keep them in one even layer for the most consistent cooking.
Pour the remaining sauce mixture evenly over the frozen manicotti, making sure all of the pasta is covered. Use a spoon to gently nudge sauce down between any gaps so no dry spots are peeking out.
Sprinkle 1 cup of the shredded mozzarella cheese evenly over the top of the saucy manicotti. Reserve the remaining 1 cup of cheese for later.
Cover the slow cooker with the lid and cook on LOW for 4 to 5 hours, or on HIGH for 2 to 3 hours, until the manicotti are heated through and tender when pierced with a fork and the sauce is bubbling around the edges.
About 15 to 20 minutes before serving, lift the lid and sprinkle the remaining 1 cup of shredded mozzarella cheese evenly over the top. Cover again and continue cooking on LOW (or keep it on WARM if everything is already hot) just until the cheese is melted and gooey.
Once the cheese is melted, turn the slow cooker to WARM if you’re serving at a gathering or cookout. Use a large spoon or spatula to carefully scoop out the manicotti, keeping as much of the filling and sauce together as possible. Serve hot with extra sauce from the crock spooned over the top.
Variations & Tips
You can easily tailor this slow cooker manicotti to your family’s tastes. For meat lovers, stir 1/2 to 1 pound of cooked and drained ground beef, Italian sausage, or ground turkey into the sauce before pouring it over the frozen manicotti (this technically adds an ingredient, but it’s a great option when you’re not strictly sticking to four). If your kids are picky about texture, choose a very smooth marinara sauce or blend a chunkier sauce briefly before using. For extra cheesiness, swap part of the mozzarella for shredded Italian blend or sprinkle a little grated Parmesan over the top with the final layer of cheese. To sneak in veggies, serve with a side of roasted broccoli or a big salad, or stir a small amount of very finely chopped spinach into the sauce (frozen, thawed spinach squeezed dry works well but also counts as an extra ingredient). If you need this to be vegetarian, simply use a meatless marinara and skip any meat additions. For a cookout, keep the slow cooker on WARM, stir gently every so often to keep the sauce from sticking to the sides, and keep the lid on when not serving so the dish stays at a safe temperature. For food safety, always start with fully frozen, commercially prepared stuffed manicotti and keep them refrigerated or frozen until you’re ready to assemble. Cook on HIGH or LOW only as directed, and don’t leave the slow cooker on the WARM setting for more than 2–3 hours after cooking. Leftovers should be cooled slightly, then stored in shallow containers in the refrigerator within 2 hours and eaten within 3–4 days, or frozen for longer storage. Reheat leftovers until they are steaming hot in the center before serving.