Sweet Potato Casserole
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Most Sweet Potato Casserole is dessert pretending to be a side dish. Not this one. Think a smooth cinnamon and vanilla base, marshmallows toasting in the middle, and a buttery cornflake pecan crunch around the edge. I haven’t changed my Sweet Potato Casserole since 2015 and I don’t plan to. Sweet but not too sweet, crunchy on top, and you can make most of it a day ahead.
Why This Sweet Potato Casserole Has Both Toppings
Most recipes make you pick a side. Marshmallows, or a pecan streusel. One camp or the other, and people have strong feelings about it.
I put both on, and I keep them separate.
Marshmallows go in the middle, in a patch. The cornflake and pecan mix goes around the outside. So you get a soft toasted marshmallow bit and a crunchy buttery bit on the same plate, and nobody has to be disappointed.
Cornflakes aren’t traditional, but crushed with melted butter, brown sugar and pecans they bake into something crisp and caramelly that holds up next to all that soft sweet potato. A regular streusel goes soggy on top of a casserole. Cornflakes don’t.
The base itself is mashed sweet potato with brown sugar, butter, cinnamon and vanilla. There’s only a quarter cup of sugar in 3 pounds of sweet potatoes, which is less than most recipes use. Sweet potatoes are already sweet. They don’t need the help.
Ingredients in Sweet Potato Casserole
- Sweet potatoes (3 pounds): About 5 or 6 large ones, peeled, cubed and cooked. There’s a section below on cooking them.
- Brown sugar (¼ cup for the base, 1 tablespoon for the topping): Not much, on purpose. You can add more if your family likes it sweeter, but I’d taste it first.
- Butter (¼ cup for the base, 1 tablespoon for the topping): Unsalted. You can use margarine if that’s what you have.
- Ground cinnamon (½ teaspoon): Just enough to warm it up.
- Vanilla extract (1 teaspoon): It makes the whole thing taste rounder.
- Egg (1): This is what keeps the casserole from being a bowl of mashed sweet potato. It sets as it bakes and gives you something you can cut into.
- Milk (¼ cup): I use whole milk. Anything you have will work.
- Salt (¼ teaspoon): With this much sugar you need it.
- Cornflakes (1 cup, crushed): The topping that doesn’t go soggy. Crush them in a bag with your hands, not in a food processor, or you’ll end up with dust.
- Pecans (¼ cup, chopped): You can use walnuts instead, or leave the nuts out if someone at the table can’t have them.
- Mini marshmallows (1 cup): Mini, not regular. They toast evenly and they don’t take over.
How To Cook Sweet Potatoes
You need 3 pounds, which is about 5 or 6 large sweet potatoes. Any of these will work and I use whichever suits the day.
- Microwave. Fastest. Poke each potato 5 or 6 times with a fork, then microwave 5 to 10 minutes per potato. Add about 2 minutes for each extra one. Turn them halfway. If they’re still firm, go another minute at a time.
- Boiled. Peel them, cube them, and boil in a big pot over medium high heat for about 20 minutes, until a fork slides in easily. Drain them really well.
- Baked. 375°F for 30 minutes to an hour, depending on size. Prick them all over and rub them with a little oil first. This one takes the longest but it gives you the best flavor, because the sugars concentrate instead of leaching into water.
However you cook them, drain or dry them well. Extra water in the mash means a loose casserole that never quite sets.
Sweet Potatoes Or Yams?
Almost certainly sweet potatoes, whatever the label says.
Real yams are a completely different vegetable. They’re starchy, dry, with rough bark like skin, and they’re mostly sold in African and Caribbean markets. If you’re in a regular North American grocery store, you are looking at sweet potatoes.
The confusion goes back decades. When orange fleshed sweet potatoes showed up alongside the paler ones already being sold, growers called them yams to tell them apart, and the name stuck. The canned ones labeled yams are sweet potatoes too.
So buy whatever says sweet potato or yam, as long as the flesh is orange. That’s the one you want here.
How To Make Sweet Potato Casserole
Get Set Up: Oven to 350°F, and grease a 9×13 inch baking dish.
Mash The Base: Cooked sweet potatoes into a large bowl with the brown sugar, butter, cinnamon, vanilla, milk, egg and salt. Mash it all together.
A potato masher gives you a bit of texture. A hand mixer gives you something smoother and more like a souffle. Both are good, so go with whichever you like better.
Taste it before the egg goes in if you’re unsure about the sweetness. It’s much easier to fix now than later.
First Bake: Spread it into the dish and bake for 30 minutes.
Mix The Topping While It Bakes: Crushed cornflakes, chopped pecans, melted butter and brown sugar, all tossed together in a bowl. It’ll look like buttery crumbs, which is right.
Add The Topping: Pull the dish out. Put the marshmallows in a patch in the middle, then sprinkle the cornflake mix around them so it covers the outside edge.
Second Bake: Back in for another 10 minutes, until the marshmallows are puffed and golden and the cornflakes have toasted.
Keep an eye on it. Marshmallows go from golden to black faster than seems fair.
Let It Rest: 10 to 15 minutes before you serve it. The casserole firms up as it sits and soaks up any extra liquid, so you get clean scoops instead of a puddle.
The Topping
Mine is a patch of mini marshmallows in the middle with a cornflake, pecan and brown sugar crumble around the outside.
If you want to change it:
- All marshmallow. Cover the whole top and skip the cornflakes. This is the version most people grew up with.
- All crumble. Double the cornflake mix and leave the marshmallows out. Better if the sweetness is already pushing it for you.
- Pecan streusel instead. Flour, brown sugar, butter and pecans. It’s the classic, but it does soften where it sits on the casserole, which is the reason I use cornflakes.
- No nuts. Leave the pecans out entirely. The cornflakes and butter still crisp up fine on their own.
Whatever you do, put the topping on partway through baking rather than at the start. Marshmallows added at the beginning will be charcoal by the end.
Make It Ahead
Everyone wants the oven on Thanksgiving, so this is a good one to get out of the way early.
Up to 3 days ahead: Make the base, spread it in the dish, let it cool all the way, then cover and refrigerate. Leave the topping off.
On the day: Take it out while the oven heats up, so it isn’t going in fridge cold. Bake 35 to 40 minutes instead of 30, since it’s starting colder. Then add the marshmallows and cornflake mix and give it the last 10 minutes.
The topping can be mixed ahead too. Keep it in a sealed container at room temperature and it’ll stay crisp.
Freezing: You can freeze the unbaked base for up to 3 months. Thaw it overnight in the fridge and bake as usual. I wouldn’t freeze it with the topping on.
Storage and Reheating
Fridge: Up to 5 days in a sealed container.
Reheating: 350°F for 15 to 20 minutes, covered with foil so the marshmallows don’t burn again. You can microwave a single portion, but the topping goes soft.
To bring the crunch back, take the foil off for the last few minutes.
More Delicious Recipes To Try
- Roasted Sweet Potatoes – The simple version, for a night that isn’t Thanksgiving.
- Cheesy Mashed Potatoes with Bacon and Chives – The other potato on the table.
- Old Fashioned Green Beans – Something green to cut through all of this.
- Quick Yeast Dinner Rolls – Fast enough to make the same day.
- Caramelized Onion Gruyere Mashed Potatoes – Over on All My Cravings, if you want to show off a little.
- Easy Oven Roasted Potatoes – From Craving Home Cooked, and they go with everything.
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Sweet Potato Casserole
Video
Ingredients
- 3 pound sweet potatoes (or yams, peeled and cut into cubes then cooked, about 5 or 6 large)
- ¼ cup brown sugar
- ¼ cup butter (unsalted, or margarine)
- ½ teaspoon cinnamon (ground)
- 1 teaspoon vanilla extract
- 1 egg
- ¼ cup milk (I used 3.25%)
- ¼ teaspoon salt (or to taste)
For Topping
- 1 cup cornflakes (crushed)
- ¼ cup pecans (chopped)
- 1 tablespoon butter (unsalted, melted)
- 1 tablespoon brown sugar (packed)
- 1 cup mini marshmallows
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Instructions
- Preheat the oven to 350°F and grease a 9×13 inch baking dish.
- In a large bowl, mash 3 pounds cooked sweet potatoes with ¼ cup brown sugar, ¼ cup butter, ½ teaspoon cinnamon, 1 teaspoon vanilla, ¼ cup milk, 1 egg and ¼ teaspoon salt. You can use a hand mixer if you’d rather. Spread the mixture into the dish and bake for 30 minutes.
- While the casserole bakes, toss 1 cup crushed cornflakes, ¼ cup chopped pecans, 1 tablespoon melted butter and 1 tablespoon brown sugar together in a bowl. Place 1 cup mini marshmallows in the center of the casserole, then sprinkle the cornflake mixture around them.
- Return the dish to the oven and bake for another 10 minutes, or until the marshmallows are puffed and golden brown. Let it rest 10 to 15 minutes before serving.
Notes
- Drain the sweet potatoes well, especially if you boil them. Extra water makes a loose casserole that never sets.
- Taste the base before you add the egg if you’re unsure about the sweetness. Easier to fix now than later.
- Crush the cornflakes by hand in a bag. A food processor turns them to dust.
- Watch the last 10 minutes. Marshmallows go from golden to burnt quickly.
- Let it rest 10 to 15 minutes. It firms up as it sits and you get clean scoops.
- Make ahead: Prepare the base without the topping, cool completely, cover and refrigerate up to 3 days. Add 5 to 10 minutes to the first bake since it’s going in cold.
Nutrition Information
Notice: Nutrition is auto-calculated for your convenience. Where relevant, we recommend using your own nutrition calculations.
Can I make it ahead?
Yes, up to 3 days. Make the base, cool it, cover it and keep it in the fridge without the topping. Add 5 to 10 minutes to the first bake because it’s going in cold.
Why is my casserole watery?
The sweet potatoes held too much water. If you boil them, drain them really well and let them sit a minute to steam dry. Letting the baked casserole rest 10 to 15 minutes helps too.
Can I use canned sweet potatoes?
You can, and it saves a lot of time. Drain them well and use about 3 pounds worth. They’re usually softer and sweeter than fresh, so taste before you add all the sugar.
Do I have to use marshmallows?
Not at all. Double the cornflake topping and leave them out. The casserole is already sweet enough to stand on its own.
Can I make it without nuts?
Yes. Leave the pecans out and the cornflake topping still crisps up fine.
Is this a dessert or a side dish?
A side, though I know it sits right on the line. There’s only a quarter cup of sugar in 3 pounds of sweet potatoes, which keeps it on the savory end of sweet. If you want it further that way, cut the brown sugar in half.
How far ahead can I mix the topping?
A day or 2, kept in a sealed container at room temperature. Don’t refrigerate it or the cornflakes go soft.
