Sweet Potato Casserole with Canned Yams and Marshmallows

Sweet potato casserole with canned yams and marshmallows is the dish everyone asks me to bring every holiday. It comes together in under an hour with pantry staples. This version hits that perfect balance of soft, buttery yams and a golden, gooey marshmallow top.

Why This Sweet Potato Casserole with Canned Yams Works

Canned yams are already cooked and sweet, so they mash up silky-smooth without any par-boiling. That shortcut cuts 30 minutes off the prep and still delivers a rich, caramelized casserole. The brown sugar and cinnamon pull out the natural sweetness of the yams without overpowering them.

Marshmallows on top go from soft and pillowy to bronzed and sticky in the last 5 minutes of baking. I pull the casserole out the moment they turn golden — any longer and they deflate into a chewy layer instead of a puffy, toasted cloud. That visual is half the appeal of this dish.

Ingredients

• 2 cans (15 oz each) sweet potatoes in syrup (canned yams), drained
• 3 tablespoons unsalted butter, melted
• 3 tablespoons brown sugar, packed
• 1/2 teaspoon ground cinnamon
• 1/4 teaspoon salt
• 1 large egg, beaten
• 2 cups miniature marshmallows
• 1/4 cup chopped pecans (optional)

What You Need for Sweet Potato Casserole with Canned Yams

Canned yams — drain the syrup completely before mashing. The syrup is very sweet and will make the filling too thin and cloying if left in. One quick shake of the colander is enough.

Unsalted butter — adds richness and helps the filling hold its shape. Salted butter works but reduce the added salt to a pinch.

Brown sugar — light or dark both work. Dark brown sugar gives a slightly deeper molasses note that pairs well with cinnamon.

Ground cinnamon — use fresh cinnamon from a recently opened jar. Old cinnamon tastes flat and chalky, and this dish has very few spices, so each one matters.

Egg — binds the filling so it sets firm enough to scoop cleanly. Skip the egg and the filling stays a bit soupier.

Miniature marshmallows — mini marshmallows melt faster and cover the surface more evenly than full-size ones. Full-size work but leave gaps and take longer to toast.

Pecans — optional but highly recommended. They add a crunchy layer under the marshmallows that balances the softness of the yam filling.

How to Make Sweet Potato Casserole with Canned Yams and Marshmallows

1. Preheat the oven to 350°F (175°C). Spray a 1.5-quart or 2-quart baking dish with nonstick spray.
2. Drain the canned yams thoroughly in a colander. Transfer to a large mixing bowl.
3. Mash the yams with a fork or potato masher until smooth. A few small lumps are fine.
4. Add the melted butter, brown sugar, cinnamon, salt, and beaten egg. Stir until fully combined.
5. Spread the yam mixture evenly into the prepared baking dish.
6. If using pecans, scatter them over the filling in an even layer.
7. Bake uncovered for 30 minutes until the filling is set and the edges begin to pull away slightly.
8. Remove from the oven. Spread the miniature marshmallows evenly over the top.
9. Return to the oven for 5 to 8 minutes until the marshmallows are golden and puffed. Watch closely — they can burn fast.
10. Serve immediately while the marshmallow topping is warm and soft.

Sweet Potato Casserole Variations

Brown Sugar Pecan Streusel Topping

Mix 1/4 cup flour, 1/4 cup brown sugar, 2 tablespoons cold butter, and 1/2 cup chopped pecans into a crumbly streusel. Spread over the filling before baking instead of marshmallows. The result is crunchier and less sweet — a good choice if the rest of the meal is already sugary.

Marshmallows and Streusel Both

Layer the pecan streusel first, then add marshmallows on top in the last 5 minutes of baking. This gives you both a crunchy nut layer and the classic golden marshmallow top — a crowd-pleaser that covers both camps at the table.

Spiced Version

Add 1/4 teaspoon ground nutmeg and 1/8 teaspoon ground cloves to the yam filling along with the cinnamon. The extra warm spices deepen the holiday flavor and work especially well if you are serving this alongside a savory, herb-heavy main dish.

Coconut Milk Version

Replace the butter with 3 tablespoons full-fat coconut milk for a dairy-free take. The coconut flavor is subtle but gives the filling a slightly tropical note that pairs unexpectedly well with the toasted marshmallows and cinnamon.

Tips for the Best Sweet Potato Casserole with Canned Yams

• I always drain the canned yams over the sink for a full minute — excess syrup makes the filling wet and the casserole won’t set properly.
• Beat the egg before adding it. Stirring a whole unbeaten egg into warm yam filling can leave streaks of cooked white if the filling is still hot.
• Do not skip the salt. Even a small amount of salt sharpens the sweetness of the brown sugar and cinnamon and keeps the dish from tasting one-dimensional.
• Spread the marshmallows in a single, even layer. A thick pile in the center means the middle stays raw while the edges char.
• Keep the oven door cracked after adding marshmallows so you can check every two minutes. The window from golden to burned is narrow.
• Make this casserole a day ahead and refrigerate before the marshmallow step. Add marshmallows right before baking on the day of serving.

Make Ahead & Storage

This casserole is one of my favorite make-ahead Thanksgiving dishes. I assemble the yam filling in the baking dish the night before, cover it tightly with plastic wrap, and refrigerate overnight. On the day, I pull it out 30 minutes before baking to take the chill off, then bake and top with marshmallows as usual.

Leftovers keep in the fridge for up to 4 days, covered. Reheat individual portions in the microwave for 60 to 90 seconds. The marshmallows deflate when refrigerated but still taste good. To re-puff them, add a fresh layer of mini marshmallows and broil for 2 minutes. This casserole does not freeze well after baking — the marshmallows turn rubbery and the filling weeps liquid when thawed.

Common Questions

Can I use fresh sweet potatoes instead of canned yams?

Yes. Bake or boil 2 pounds of sweet potatoes until fork-tender, then peel and mash. The flavor will be slightly earthier and less sweet than canned yams, so you may want to add an extra tablespoon of brown sugar to compensate.

What is the difference between sweet potatoes and canned yams?

In the US, what is sold as canned yams is actually sweet potato. True yams are a different plant, starchier and less sweet. Canned yams are softer, sweeter, and pre-cooked in syrup — they mash much faster than fresh sweet potatoes.

Can I make this casserole without eggs?

Yes. Leave out the egg and the filling will still taste great — it just won’t set as firm. It will be slightly more scoopable rather than sliceable. This makes it a good option for guests with egg allergies.

How do I keep marshmallows from burning on top?

Watch them closely and position the rack in the center of the oven, not the top. The marshmallows only need 5 to 8 minutes at 350°F. If your oven runs hot, check at 4 minutes. You want golden edges, not brown.

Can I add mini marshmallows inside the filling too?

Yes. Fold 1/2 cup of mini marshmallows into the yam filling before spreading it in the dish. They melt into the filling during baking and add small pockets of extra sweetness throughout.

Sweet potato casserole with canned yams and marshmallows is the easiest holiday side dish I make all year. Save this recipe and tap the link for all the details.