I mashed fresh sweet potatoes with brown sugar and cinnamon, piled them into a casserole and topped everything with ooey-gooey marshmallows, and my Sweet Potatoes With Marshmallows hides a tiny twist that will have you eager for the recipe.

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I love how a simple tray of roasted sweet potatoes can change the whole table. I take tender sweet potatoes and pile them into a baking dish, then I bury them under a cloud of marshmallows so the top goes golden and sticky.

People always say it reminds them of Ruth Chris’s Sweet Potato Casserole and sometimes someone even calls it a Sweet Potato Marshmallow Casserole knock off, which I don’t mind. It’s not perfect every time, I burn the edges sometimes, but that burned bit?

strangely addictive. Try it once, you’ll see why everyone argues over the last scoop.

Ingredients

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Sweet potatoes add fiber and vitamin A, earthy sweetness that fills the dish
Brown sugar brings caramel sweetness and extra carbs, not the healthiest choice
Butter adds rich fat and flavor, helps texture but high in saturated fat
Eggs give protein and structure, they bind the casserole and add richness
Whole milk contributes creaminess, a little fat and calcium, mild dairy taste
Warm spices like cinnamon and nutmeg add aroma, mild sweetness and depth
Marshmallows make it gooey sweet, mostly sugar with little nutrition, kids love it
Kosher salt lifts flavors, no calories but use sparingly for health reasons

Ingredient Quantities

3 pounds sweet potatoes (about 4 large), peeled and cubed

1/2 cup packed light brown sugar

1/4 cup (4 tablespoons) unsalted butter melted

2 large eggs, lightly beaten

1 teaspoon vanilla extract

1/2 teaspoon ground cinnamon

1/4 teaspoon ground nutmeg optional

1/2 teaspoon kosher salt

1/4 cup whole milk

3 cups mini marshmallows (about a 10 ounce bag)

How to Make this

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1. Preheat oven to 350 F (175 C) and grease a 9×13 inch casserole dish.

2. Put 3 pounds peeled, cubed sweet potatoes in a big pot, cover with cold water, bring to a boil and simmer until fork tender about 15 to 20 minutes; drain well.

3. Return potatoes to the pot or a bowl and mash until smooth or slightly chunky if you like texture. For super smooth, push them through a ricer.

4. Let the potatoes cool a minute so the eggs wont scramble, then stir in 1/2 cup packed light brown sugar, 1/4 cup melted unsalted butter, 2 lightly beaten large eggs, 1 teaspoon vanilla extract, 1/2 teaspoon ground cinnamon, 1/4 teaspoon ground nutmeg if using, 1/2 teaspoon kosher salt and 1/4 cup whole milk. Mix until everything is well combined and taste for sweetness or salt.

5. Spoon the sweet potato mixture into the prepared dish and smooth the top with a spatula.

6. Bake uncovered for 20 to 25 minutes until the edges are set and the center is hot and slightly bubbling.

7. Remove from oven and evenly scatter 3 cups mini marshmallows (about a 10 ounce bag) over the top.

8. Put the dish back in the oven and broil on high for 30 to 90 seconds until the marshmallows are puffed and golden, watching like a hawk so they dont burn. If you dont have a broiler or worry about burning, just bake at 350 F for another 5 to 10 minutes until marshmallows are melted.

9. Let the casserole rest about 5 minutes so the topping sets, then serve warm. Quick tip: if you want a crunchy top, toss a few chopped pecans with the marshmallows before broiling.

Equipment Needed

1. Oven (preheat to 350 F)

2. 9×13 inch casserole dish, well greased

3. Large stockpot for boiling the sweet potatoes

4. Colander or fine mesh strainer to drain

5. Potato masher or ricer for smooth or slightly chunky texture

6. Large bowl or just use the pot for mashing and mixing, its up to you

7. Measuring cups and measuring spoons

8. Rubber spatula and wooden spoon to mix and smooth the top

9. Oven mitts and a rimmed baking sheet to catch drips while broiling

FAQ

Q: How should I cook the sweet potatoes before mixing the casserole? A: You can boil them 20 to 25 minutes until fork tender or roast at 400°F for 45 to 50 minutes for more caramelized flavor. Drain well, mash, then fold in the brown sugar, melted butter, eggs, vanilla, spices, milk and salt. Roasting gives better depth but boiling is quicker.

Q: What temperature and time do I bake the assembled casserole? A: Bake the filled dish at 350°F for about 20 to 30 minutes until it is hot and bubbling at the edges. Then top with the mini marshmallows and bake another 5 to 10 minutes until the marshmallows are golden. Watch closely so they dont burn.

Q: Can I make this ahead or freeze it? A: Yes. You can assemble up to 24 hours ahead and keep covered in the fridge. For freezing, do not add marshmallows, wrap tight and freeze up to 2 months. Thaw overnight in the fridge, add marshmallows, then bake as directed.

Q: Any good swaps for marshmallows or ways to make it vegan? A: Replace marshmallows with a pecan streusel if you prefer crunchy top: mix chopped pecans, brown sugar, a little flour and melted butter then sprinkle on top. For vegan, use plant milk, vegan butter and vegan marshmallows or stick with the streusel.

Q: My casserole came out runny what happened and how do I fix it? A: Runny filling usually means too much liquid from the potatoes or milk, or not enough egg to set. To fix before baking stir in 1 to 2 tablespoons cornstarch or an extra egg yolk, mash more to release steam, then bake until set.

Q: How long will leftovers keep and best way to reheat? A: Store covered in the fridge for 3 to 4 days. Reheat single portions in the microwave or the whole dish covered at 325°F for 20 to 30 minutes until warmed through. If the marshmallows get soggy, re-toast them briefly under the broiler or use a kitchen torch.

Sweet Potato Casserole Recipe Substitutions and Variations

Sweet potatoes: swap with equal amount of cooked mashed butternut squash, pumpkin, or canned sweet potato puree — use the same volume (about 3 to 4 cups mashed for 3 pounds). It’ll change the flavor a bit, but the texture stays close.
Light brown sugar: use coconut sugar 1:1 for a less refined option, or stir 1 cup granulated sugar with 1 tablespoon molasses to make 1 cup light brown sugar if you don’t have any.
Unsalted butter, melted: use coconut oil 1:1 for a dairy free version, or melted margarine/salted butter (if using salted, cut back on the added salt).
Mini marshmallows: replace with a pecan-brown sugar streusel (eg 1 cup chopped pecans, 1/2 cup flour, 1/3 cup brown sugar, 4 tbsp cold butter cut in) or a simple meringue (2 egg whites whipped with 1/3 cup sugar) for a less cloying topping.

Pro Tips

1) Drain and dry the potatoes extra well before mixing, then return them to the warm pot for a minute to let surface moisture evaporate. if you want super silky texture push them through a ricer, but if you like a little bite leave some small chunks.

2) Taste and tweak as you go dont just dump the sugar in. a little extra salt, a spoon of maple syrup or a splash of orange juice or bourbon can wake the whole dish up without making it weird.

3) Marshmallow finish needs babysitting — broil for only a few seconds and stand there watching, rack one notch below the broiler but not touching. if you worry about burning, torch the top or bake a few extra minutes at 350 until melted instead.

4) Prep hacks: you can make the casserole a day ahead and keep the marshmallows separate, then add and finish under the broiler just before serving. leftovers reheat well in a low oven, cover with foil so the marshmallows dont scorch.