This Marshmallow Pecan Sweet Potato Casserole is a comforting, sweet‑and‑nutty side dish that combines creamy mashed sweet potatoes with a crunchy pecan‑marshmallow topping. It’s a perfect balance of smooth and crispy, ideal for holidays or cozy family dinners.

Why I’ll Love This Recipe

I love this casserole because it brings together several textures and flavors in harmony: the softness of sweet potatoes, the warmth of cinnamon‑like sweetness, and the crisp, toasty crunch from pecans and marshmallows. The topping bakes up golden, creating a delightful contrast. It’s indulgent but still rooted in classic holiday comfort.

ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

For the sweet potato layer:

3 cups mashed sweet potatoes
¾ cup granulated sugar
½ cup whole milk
1 stick unsalted butter, melted
2 large eggs, well beaten
1 teaspoon pure vanilla extract

For the topping:

½ stick unsalted butter, melted
½ cup brown sugar
½ cup all‑purpose flour
⅓ cup whole milk
½ cup chopped pecans
1 cup mini marshmallows

directions

Preheat the oven to 350 °F (≈ 175 °C).
In a mixing bowl (or in a stand mixer with paddle), beat together the mashed sweet potatoes, granulated sugar, milk, melted butter, beaten eggs, and vanilla extract until well combined and smooth.
Butter a 9×13‑inch (or similar oval) glass baking dish or casserole dish, then pour the sweet potato mixture into it and spread evenly.
In a medium bowl, combine the melted butter, brown sugar, flour, and milk. Stir until a cohesive mixture forms.
Fold in the chopped pecans and mini marshmallows into the topping mixture.
Spoon or spread that topping evenly over the sweet potato base.
Bake in the preheated oven for 30 to 40 minutes, until the topping is golden brown and the sweet potato layer is bubbly around the edges.
Let it cool slightly before serving so the topping can set a bit.

Servings and timing

Yields: 10 to 12 servings
Prep time: 60 minutes
Total time: about 1 hour and 40 minutes

Variations

Swap out pecans for walnuts if preferred.
Add a pinch of cinnamon or nutmeg into the sweet potato mixture for extra warmth.
Use half maple syrup in place of some granulated sugar for a maple‑sweet flavor.
If you prefer a less sweet version, reduce brown sugar slightly in the topping.
For a lighter topping, you can skip some of the flour and increase pecans / marshmallows a bit.

storage/reheating

Store leftovers in an airtight container or cover the dish with foil or plastic wrap. Refrigerate for up to 3 to 4 days.
To reheat, place in a 325 °F (≈ 160 °C) oven for 15–20 minutes or until warmed through. You can also reheat individual portions in the microwave, but the topping may soften.

FAQs

What kind of sweet potatoes should I use?

I use standard orange‑fleshed sweet potatoes. I bake or boil them until very tender, then mash until smooth before incorporating into the recipe.

Can I prepare this ahead of time?

Yes — you can assemble everything (sweet potato layer + topping) and refrigerate (covered) for a few hours before baking. Bring back to room temperature before putting it into the oven so it bakes more evenly.

Can I use non‑dairy milk instead of whole milk?

Yes, you can substitute a non‑dairy milk like almond milk, coconut milk, or oat milk. The texture might shift slightly, but it should still work.

What if I don’t have mini marshmallows?

You can roughly chop regular marshmallows into smaller bits. They’ll still melt and toast nicely, though the texture will differ slightly from minis.

Can I freeze this casserole?

I don’t recommend freezing after baking, because the topping may lose its crispness. However, you could freeze the sweet potato base (without topping) for short term, then thaw and add topping before baking.

Conclusion

This Marshmallow Pecan Sweet Potato Casserole is one of my favorite dishes to bring to holiday meals or family dinners. The creamy sweet potatoes and crunchy, toasty topping work beautifully together, and it’s flexible enough to tweak to your tastes. I hope you enjoy making and sharing it as much as I do.