When the holidays roll in and the kitchen fills with warm, nostalgic aromas, this Sweet Potato Casserole with Marshmallows is the dish that makes everyone’s eyes light up. The first spoonful gives you a cloud of toasty, caramelized marshmallows, a buttery layer of silky sweet potatoes, and a delicate crunch from a brown sugar–pecan topping. It’s cozy, indulgent, and exactly what a festive table deserves.
I love that this classic Thanksgiving side dish feels celebratory yet simple. We boil and mash fresh sweet potatoes until they’re tender and fluffy, whisk in butter and a hint of cinnamon and vanilla, then finish with a crisp pecan crumble and a blanket of marshmallows that toast to golden perfection in the oven. The contrast—creamy, crunchy, sticky, and sweet—makes every bite feel like a holiday hug. This is absolutely one to pin and save for your big feast!
Why You’ll Love It
- Iconic holiday flavor: A classic sweet potato casserole with marshmallows and pecan topping that tastes like tradition.
- Dreamy texture: Silky, buttery sweet potatoes meet a crisp, caramelized pecan crumble and toasty marshmallows.
- Make-ahead friendly: Prep the filling in advance; add topping and marshmallows before baking—perfect for Thanksgiving timing.
- Party-size serving: Bakes in a 9×13-inch dish to feed a crowd with ease.
- Simple ingredients: Pantry staples—sweet potatoes, brown sugar, butter, pecans, and mini marshmallows—come together fast.
- Guaranteed crowd-pleaser: Always the first empty dish at holiday dinners, Friendsgiving, and potlucks.
Time Needed
- Prep Time: 35 minutes
- Cook Time: 35 minutes
- Total Time: 1 hour 10 minutes
- Servings: 12
Ingredients
- For the sweet potato filling
- 4 large sweet potatoes, peeled and cut into large chunks (about 9 cups)
- 1/2 cup unsalted butter, melted
- 1 cup brown sugar
- 1/2 teaspoon fine salt
- 1/2 teaspoon ground cinnamon
- 1 teaspoon vanilla extract
- 1/4 teaspoon ground nutmeg
- For the pecan topping
- 4 tablespoons unsalted butter, melted
- 1/3 cup brown sugar
- 2 tablespoons all-purpose flour
- 1/2 teaspoon fine salt
- 1 1/4 cups finely chopped pecan pieces
- For the marshmallow layer
- 10 ounces mini marshmallows
Step-by-Step Instructions
- Boil the sweet potatoes Place the peeled chunks in a large pot, cover with cold water, and bring to a boil. Cook until the potatoes are fork-tender and starting to fall apart, 15–20 minutes.
- Mash until silky Drain well and return to the warm pot. Mash until smooth and steamy. Stir in melted butter, brown sugar, salt, cinnamon, vanilla, and nutmeg. Taste and adjust sweetness and salt.
- Mix the pecan crumble In a bowl, combine melted butter, brown sugar, flour, salt, and pecan pieces. Stir until evenly moistened and sandy-crisp.
- Assemble the casserole Grease a 9×13-inch baking dish. Spread the sweet potato mixture in an even layer. Sprinkle the pecan topping evenly over the surface.
- Top with marshmallows Cover the pecans with mini marshmallows in a thick, even blanket—edge to edge. This ensures a gorgeous, evenly toasted top.
- Bake to golden perfection Bake at 350°F for 25–35 minutes, until the filling is hot and bubbly and the marshmallows are toasted a deep golden brown. Watch closely in the last few minutes for that perfect toasty finish.
- Serve warm Let the casserole rest for 5–10 minutes to set slightly, then scoop into bowls or onto plates while the marshmallows are still gooey.
Variations to Try
- Maple Kissed: Replace 1/4 cup of the brown sugar in the filling with pure maple syrup for a cozy, caramel note.
- No-Nut Option: Skip the pecans and use a simple brown sugar streusel (butter + brown sugar + flour + pinch of salt) beneath the marshmallows.
- Marshmallow Only: Love it extra gooey? Omit the crumble and use a double layer of mini marshmallows added in the last 15 minutes.
- Crunch Lovers: Add crushed graham crackers to the pecan topping for a toasty, cookie-like crunch.
Tips from Chef Emma
- Drain well: Excess water can make the filling loose. After draining, return potatoes to the warm pot to steam off moisture.
- Season generously: Sweet potatoes shine with enough salt to balance their natural sweetness.
- Golden, not burnt: Marshmallows toast quickly—keep an eye on the last 5 minutes for that perfect bronzed top.
- Make ahead: Prepare the filling up to 2 days in advance. Refrigerate, then top with crumble and marshmallows right before baking.
- Smooth vs. rustic: Mash fully for a silky texture or leave a few soft chunks for a heartier bite.
Nutrition Info per Serving
- Serving Size: 1 square (about 1/12 of the pan)
- Calories: 420
- Carbohydrates: 61g
- Sugars: 41g
- Fat: 20g
- Protein: 3g
- Sodium: 260mg
Frequently Asked Questions
- Can I make this sweet potato casserole ahead?
Yes—assemble the filling and store covered in the fridge for up to 48 hours. Add the pecan topping and marshmallows just before baking so they stay crisp and toasty. - Can I use canned yams?
You can, but fresh sweet potatoes deliver the best flavor and texture. If using canned, drain very well and reduce the added sugar to taste. - How do I keep marshmallows from melting too much?
Use mini marshmallows and bake until just golden. If they brown too fast, tent loosely with foil in the last minutes. - Nut-free option?
Absolutely—swap the pecans for an oat-and-brown-sugar streusel or omit the crumble entirely and go marshmallow-only. - How should I reheat leftovers?
Warm in a 300–325°F oven until heated through to re-crisp the topping. The microwave works in a pinch but won’t keep the marshmallows as toasty.
Final Thoughts
From the first whiff of cinnamon to the last caramelized bite, this Sweet Potato Casserole with Marshmallows brings pure holiday comfort. It’s simple, celebratory, and designed to make your Thanksgiving table shine. Save this recipe to your holiday board so it’s ready for the big day!
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Sweet Potato Casserole with Marshmallows – Silky, Buttery & Crowd-Pleasing Holiday Side
- Total Time: 1 hour 10 minutes
- Yield: 12 servings 1x
Description
This Sweet Potato Casserole with Marshmallows layers silky, buttery sweet potatoes with a crunchy brown sugar–pecan topping and a blanket of golden, toasty mini marshmallows. It’s a classic Thanksgiving side dish that’s easy to make ahead and guaranteed to be a family favorite.
Ingredients
- For the sweet potato filling
- 4 large sweet potatoes, peeled and cut into large chunks (about 9 cups)
- 1/2 cup unsalted butter, melted
- 1 cup brown sugar
- 1/2 teaspoon fine salt
- 1/2 teaspoon ground cinnamon
- 1 teaspoon vanilla extract
- 1/4 teaspoon ground nutmeg
- For the pecan topping
- 4 tablespoons unsalted butter, melted
- 1/3 cup brown sugar
- 2 tablespoons all-purpose flour
- 1/2 teaspoon fine salt
- 1 1/4 cups finely chopped pecan pieces
- For the marshmallow layer
- 10 ounces mini marshmallows
Instructions
Boil the sweet potatoes
Place peeled chunks in a large pot, cover with cold water, and bring to a boil. Cook until fork-tender and starting to fall apart, 15–20 minutes.
Mash until silky
Drain well and return to the warm pot. Mash smooth. Stir in melted butter, brown sugar, salt, cinnamon, vanilla, and nutmeg. Taste and adjust seasoning.
Mix the pecan crumble
In a bowl, combine melted butter, brown sugar, flour, salt, and pecan pieces until evenly moistened.
Assemble the casserole
Grease a 9×13-inch baking dish. Spread the sweet potato mixture in an even layer and sprinkle the pecan topping evenly over the surface.
Top with marshmallows
Cover with mini marshmallows in a thick, even layer.
Bake to golden perfection
Bake at 350°F for 25–35 minutes, until hot and bubbly with deeply golden marshmallows. Watch closely near the end.
Serve warm
Let rest 5–10 minutes, then scoop and enjoy while the topping is toasty and gooey.
Notes
Make-ahead: Prepare the filling up to 2 days in advance and refrigerate. Add the pecan topping and marshmallows just before baking. For perfect color, watch the marshmallows closely in the last 5 minutes. Reheat leftovers in a 300–325°F oven to re-crisp the top.
- Prep Time: 35 minutes
- Cook Time: 35 minutes
- Category: Side Dish
- Method: Baked Casserole
- Cuisine: American
Nutrition
- Serving Size: 1/12 pan
- Calories: 420
- Sugar: 41g
- Sodium: 260mg
- Fat: 20g
- Carbohydrates: 61g
- Protein: 3g
Keywords: sweet potato casserole with marshmallows, Thanksgiving side dish, pecan topping, holiday casserole, make ahead