Sweet Potato Casserole with Marshmallows

BY Emily Parker December 24, 2025

Holiday gatherings often call for a centerpiece side dish that feels like a treat, and a classic Sweet Potato Casserole with Marshmallows serves that purpose beautifully. This dish manages to bridge the gap between a savory vegetable side and a decadent dessert, making it a staple for autumnal celebrations and festive family dinners. The contrast of the earthy, whipped orange potatoes against a cloud-like layer of toasted sugar creates a texture that is both nostalgic and deeply satisfying. It is the kind of recipe that guests look for as soon as they see the table set, offering a warm, spiced aroma that defines the season.

Table of Contents

Ingredients

The Potato Base

Three to three and one quarter pounds sweet potatoes (garnet or jewel varieties work best)
Two tablespoons salted butter
One quarter cup whole milk
Two tablespoons light brown sugar
One half teaspoon ground cinnamon
One half teaspoon fine sea salt (plus more to taste)

The Crunch Layer

Four tablespoons unsalted butter, softened to room temperature
One quarter cup all purpose flour
One quarter cup light brown sugar
One half cup pecans, roughly chopped
One half teaspoon ground cinnamon
One eighth teaspoon salt

The Topping

Three cups mini marshmallows

Instructions

Prepare the oven by heating it to three hundred seventy five Fahrenheit and grease an eight by eleven inch baking dish.
Peel the sweet potatoes and cut them into uniform two inch chunks.
Boil the potato chunks in a large pot of water for seven to nine minutes until fork-tender.
Drain the water thoroughly and return the potatoes to the warm pot to evaporate excess moisture.
Add the butter, milk, brown sugar, cinnamon, and salt, then mash until the desired consistency is reached.
Spread the potato mixture into the prepared baking dish in an even layer.
In a small bowl, combine the streusel ingredients (butter, flour, sugar, pecans, cinnamon, and salt) using a fork until crumbly.
Bake the plain potato base for ten minutes (or thirty minutes if starting from the refrigerator).
Remove from the oven and top with the marshmallows and the streusel crumbles.
Return to the oven for ten to fifteen minutes until the marshmallows are golden and the streusel is set.

Step-by-Step Details

Preparing the Sweet Potatoes

When selecting your potatoes, look for those with a deep copper skin and bright orange flesh. Peeling them completely is necessary for a smooth mouthfeel. Once chopped, boiling them starting in cold water ensures even cooking. You are looking for a “fork-tender” state; the potato should yield easily when pierced but not be falling apart into a mush in the water.

Achieving the Ideal Mash

After draining, the potatoes should look matte rather than shiny. This indicates the exterior water has evaporated. If you prefer a rustic feel, use a hand masher. For a souffle-like texture that mimics high-end catering, use a hand mixer on medium speed for two minutes. The aroma at this stage should be heavy with cinnamon and the natural sweetness of the root vegetable.

Creating the Streusel

The butter for your streusel must be soft but not melted. If it is melted, the topping will turn into a flat cookie-like layer rather than distinct, crunchy pebbles. Using a fork to cut the flour and sugar into the butter creates those sought-after nooks and crannies that catch the marshmallow as it melts.

The Toasted Topping

This is the most critical stage for visual appeal. When you add the marshmallows and streusel, try to alternate them so the pecans are nestled between the white puffs. As they bake at three hundred seventy five Fahrenheit, the marshmallows will begin to expand and brown. Watch for a deep amber color on the peaks. If they remain stark white, they haven’t developed that campfire-style caramelized flavor.

Pro Tips

Dry the Potatoes: After draining the boiled potatoes, put them back in the hot pot over low heat for sixty seconds. Shaking the pot helps steam off the remaining water, preventing a runny casserole.
Salt Balance: Do not skip the salt in the potato base. It provides a necessary counterpoint to the sugar and marshmallows, preventing the dish from becoming cloyingly sweet.
Uniformity: Cut your potato chunks into the same size so they finish cooking at exactly the same time. This prevents “woody” bits in your mash.
The Broiler Trick: If your marshmallows are soft but not browning, turn on the broiler for thirty to sixty seconds. Stay at the oven door the entire time, as they can go from golden to burnt in a heartbeat.
Nut Toasting: For an even deeper flavor, toast your pecans in a dry skillet for three minutes before adding them to the streusel mix.
Flavor Boost: Use pumpkin pie spice instead of plain cinnamon if you want a more complex profile featuring nutmeg and cloves.

Variations or Substitutions

Nut-Free Option: Replace the pecans with rolled oats or toasted sunflower seeds to maintain the crunch without the allergens.
Dairy-Free Swap: Use a high-quality vegan butter stick and unsweetened almond or oat milk. The texture remains remarkably similar to the original.
Citrus Note: Add one teaspoon of fresh orange zest to the potato mash. The acidity cuts through the richness and brightens the overall flavor.
Large Marshmallow Swap: If you only have large marshmallows, snip them in half with kitchen shears. The exposed sticky center helps them adhere to the potato base.

Serving Suggestions

This dish is a powerhouse alongside roasted meats. It pairs exceptionally well with herb-crusted turkey or a salt-rubbed roast chicken. Because of its sweetness, it acts as a palate cleanser between more savory bites of stuffing or green bean casserole.

For a formal presentation, serve it in individual ramekins. This ensures every guest gets an equal portion of the toasted topping and makes for a beautiful plated display. If serving from a large dish, let it sit for five minutes after exiting the oven; this allows the marshmallow layer to “set” slightly so it doesn’t slide off the potatoes when scooped.

FAQs

Can I use canned yams for this recipe?

Yes, you can substitute canned yams, but ensure they are drained and rinsed thoroughly. Since canned versions are often packed in syrup, reduce the brown sugar in the mash to one tablespoon to avoid over-sweetening.

Why did my marshmallows disappear into the potatoes?

This usually happens if the potatoes are too watery or if the marshmallows are baked for too long at a lower temperature. High heat for a shorter duration helps the marshmallows brown on the outside before they fully liquify.

How do I make this ahead of time?

Prepare the mashed potatoes and the streusel separately up to two days in advance. Store both in the refrigerator. On the day of serving, heat the potatoes first, then add the toppings and finish the baking process as directed.

Is it possible to freeze Sweet Potato Casserole with Marshmallows?

You can freeze the mashed potato base effectively, but the marshmallow and streusel topping should only be added fresh before the final bake. Thaw the potatoes in the fridge overnight before reheating.

Nutrition Information

Nutrient	Amount per Serving
Calories	260 kcal
Protein	3 g
Carbs	38 g
Fat	11 g
Fiber	4 g
Sugar	13 g
Sodium	109 mg

Nutrition Information Disclaimer

Nutrition information is an estimate and may vary based on preparation and ingredients used.

Sweet Potato Casserole with Marshmallows

Ingredients

Instructions