Sweet Potato Casserole with Marshmallows

Ingredients for Sweet Potato Casserole with Marshmallows

See the recipe card below this post for ingredient quantities and full instructions.

For the sweet potatoes:

• Canned yams – Two 40-oz cans of cut sweet potatoes in syrup (I use Bruce’s), drained well. This is the recipe my mom always used, and canned is what makes it a 45-minute dish. See the FAQ if you want to use fresh. (Sweet potato lovers, be sure to try these Air Fryer Sweet Potato Chips!)
• Sugar – Just a little extra sweetness; the yams are already sweet from the syrup.
• Butter – One stick, unsalted.
• Eggs – Two, to set the filling.
• Vanilla – A teaspoon.

For the topping:

• Brown sugar, flour, and cold butter – Cut-up butter (not melted) is the secret to a crumble that stays crumbly instead of melting into the casserole.
• Pecans – Optional, but the crunch is the best part.
• Mini marshmallows – Any size works, but minis toast evenly and cover the top without gaps.

Variations

• Pecan-free: Leave the nuts out of the crumble; it still browns beautifully.
• Extra marshmallows: Cover the whole top for the full marshmallow-blanket effect.
• Praline instead of marshmallows: That’s my Paula Deen sweet potato casserole—melted-butter praline, no marshmallows.
• Fresh sweet potatoes: Boil or bake about 3 pounds until tender and mash before adding to the bowl. The filling will be a little less sweet, so taste before you add the sugar.

How to Make Sweet Potato Casserole with Marshmallows

1. Prep: Preheat the oven to 350°F. Drain both cans of yams well and grease a 9×13 baking dish.
2. Mix the filling: In a large bowl, add the yams, sugar, butter, vanilla, and eggs. Mash with a potato masher until mostly smooth (a few small lumps are fine).
3. Spread: Spread the filling evenly in the baking dish.
4. Make the crumble: In a separate bowl, combine the brown sugar, flour, cut-up butter, and pecans. Work it with a fork until it looks like coarse crumbs.
5. Top: Sprinkle the crumble evenly over the sweet potatoes, then scatter the marshmallows over the top.
6. Bake: Bake 30–35 minutes, until the crumble is browned and the marshmallows are melted and golden. Let it sit 10 minutes before serving.

How to Keep the Marshmallows from Burning

Marshmallows go from golden to black fast. A few things that help:

• Watch the last 10 minutes. They puff, then brown, then burn—check at 25 minutes.
• Too dark too soon? Tent the dish loosely with foil for the rest of the bake.
• Add them late if your oven runs hot. Bake with the crumble only for 20 minutes, then add the marshmallows for the final 10–15.
• Marshmallows disappeared? They melted into the topping—that happens when they go on a very hot casserole or bake too long. Minis on top of the crumble, not under it, hold their shape best.

Storage and Make-Ahead

• Make ahead: Honestly? This one is best made the day of. You can mix the filling a few hours ahead and leave it covered on the counter, then top and bake before dinner. I don’t recommend refrigerating it before or after baking—it never turns out the same. For dishes that do hold, see my make-ahead Thanksgiving side dishes.
• Leftovers: Refrigerate up to 3 days. Reheat in the microwave with the rest of your Thanksgiving leftovers, or in a 350°F oven until warm.

What to Serve It With

Crockpot Turkey Breast, 1-Hour Dinner Rolls, and Cranberry Sauce. It also belongs on any table with Cheesy Potatoes, Scalloped Potatoes, Cornbread Casserole, or Brussels Sprouts.

Frequently Asked Questions