I grew up watching dishes like this come out of warm ovens during the holidays: rich, buttery sweet potatoes topped with toasted marshmallows that melt to golden perfection. After years of testing and refining, this Southern-style sweet potato casserole keeps that classic comfort. The filling is smooth and flavorful (never watery), the marshmallow topping is gooey and caramelized, and each bite tastes like a family recipe.
This recipe was originally published in 2021 and has been updated.
Sweet Potato Casserole with Marshmallows Ingredients
- Sweet potatoes (2½–3 pounds cooked, mashed)
- ½ cup light brown sugar or brown sweetener
- 2 eggs (room temperature)
- 1 teaspoon vanilla extract
- 4 tablespoons unsalted butter, melted (measured solid = ¼ cup)
- 1 teaspoon cinnamon
- ½ teaspoon nutmeg
- ½ teaspoon salt
- 2 cups mini marshmallows (plus a handful extra if needed)
Sweet potato casserole with marshmallows is, to my mind, a dessert-style side: sweet, creamy, and best served warm. It differs from candied sweet potatoes (often called “candied yams”) primarily in texture and sweetness—candied versions are syrupy, while casserole is whipped and smooth with a toasted marshmallow topping. If you prefer a version without marshmallows, you can omit them or bake with a streusel or nut topping instead.
How to Make Marshmallow Sweet Potato Casserole
Full measurements and instructions are below. This overview covers the key steps so you can see the process at a glance.
- Preheat oven to 375°F (190°C).
- Grease a 9×13-inch baking dish.
- Combine mashed sweet potatoes, eggs, melted butter, vanilla, brown sugar, cinnamon, nutmeg, and salt in a mixing bowl.
- Beat with a hand mixer on medium until smooth, or use a blender or food processor for a silky texture.
- Spread the sweet potato mixture into the prepared baking dish.
- Top evenly with mini marshmallows, adding a few extra as needed to fully cover the surface.
- Bake 20–25 minutes, or until the marshmallows are golden and gooey. Let rest 10–15 minutes before serving.
Southern Sweet Potato Casserole Recipe
Author: Brandi Crawford
This Southern-style recipe delivers a velvety sweet potato base and a perfectly toasted marshmallow top. It’s ideal for Thanksgiving, holiday dinners, or any time you want a comforting, crowd-pleasing side or dessert.
Recipe Details
- Prep Time: 15 minutes
- Cook Time: 1 hour 5 minutes (includes baking or roasting sweet potatoes)
- Total Time: 1 hour 20 minutes
- Servings: About 6 cups (serves 6 as a side)
- Calories: Approximately 163 kcal per ½ cup serving
Equipment
- Hand mixer, blender, or food processor
- 9×13-inch baking dish
- Mixing bowl and spatula
Ingredients (1x)
- 2½–3 pounds sweet potatoes, cooked, mashed, and cooled
- ½ cup brown sugar or brown sweetener (light)
- 2 large eggs, room temperature
- 1 teaspoon vanilla extract
- 4 tablespoons unsalted butter, melted
- 1 teaspoon cinnamon
- ½ teaspoon nutmeg
- ½ teaspoon salt
- 2 cups mini marshmallows (plus extra if needed)
Instructions
- Preheat oven to 375°F.
- Grease a 9×13-inch baking dish.
- In a large bowl, mix cooled mashed sweet potatoes with eggs, melted butter, vanilla, brown sugar, cinnamon, nutmeg, and salt.
- Beat on medium until smooth and creamy.
- Spread mixture into the prepared dish and top with mini marshmallows in an even layer.
- Bake 20–25 minutes, until marshmallows are browned and gooey. Allow to rest 10–15 minutes to set before serving.
Notes
- Cooking the sweet potatoes: roast, air fry, or boil. Roasting or air frying yields drier, richer flavor; boiling can make the mixture slightly watery if not drained well.
- Air Fryer method: scrub potatoes, rub with a little oil, air fry 35–40 minutes at 400°F until soft.
- Oven roast: bake whole sweet potatoes 60–70 minutes at 400°F until tender.
- Boil: cover with water, simmer 30–40 minutes until soft; drain thoroughly.
- For a smooth filling, use a hand mixer or blender. Room-temperature eggs help the texture become light and fluffy.
- Optional additions: pecans or other nuts, added before the final marshmallow layer; a streusel topping also works well.
- You can use canned sweet potatoes—drain them very well first.
- If doubling the recipe, use a larger dish; cook time remains similar.
Nutrition
Nutrition estimates are approximate and depend on the exact brands and ingredients you use. The values provided here are a guideline—calculate using your preferred nutrition tool for precise results.
Tips for the Best Southern Sweet Potato Casserole
- Make them smooth. No one wants lumps—use a mixer or food processor for a velvety base.
- Taste and adjust. Sweet potatoes differ in sweetness; taste the filling before baking and tweak sugar or spices to suit.
- Don’t skip butter. Butter adds richness and helps the filling set.
- Warm spices matter. Cinnamon and nutmeg (or a pinch of allspice) elevate the classic flavor.
- Use mini marshmallows. They toast evenly and create that signature golden top.
- Bake in a shallow dish. More surface area means more marshmallow topping per bite.
- Let it rest. Allow 10–15 minutes after baking so the casserole firms and is easier to serve.
How to Thicken
- Cool the potatoes slightly before mixing in eggs and butter—very hot potatoes can thin the mixture.
- Mix until smooth but avoid overworking; overmixing can make the filling looser.
- Ensure the casserole is fully baked and set in the center before removing it from the oven.
Storing Sweet Potato Marshmallow Casserole
Store covered in the refrigerator for 3–4 days. Reheat in the oven at 350°F until warmed through or microwave individual portions.
Freezing
Cover tightly with plastic wrap, then foil to prevent freezer burn. Freeze up to 2 months. Thaw in the refrigerator overnight before reheating. If possible, add fresh marshmallows and bake briefly to refresh the topping.
Frequently Asked Questions and Pro Tips
In most U.S. grocery stores, labels can be confusing: what’s sold as “yams” is often a sweet potato variety. True yams are starchier and drier with rough, brown skin and are more common in Caribbean and West African cuisines.
How to cook the sweet potatoes
Roasting or air frying yields the best texture and flavor for this casserole; boiling can introduce extra water. Air fry whole sweet potatoes at 400°F for 35–40 minutes, or roast in the oven at 400°F for 60–70 minutes until tender.
Can you use canned sweet potatoes?
Yes—drain them thoroughly before mixing.
Which sweetener to use?
Light or dark brown sugar works. Brown sugar substitutes that measure 1:1 can be used if desired.
What marshmallows to use?
Mini marshmallows melt and brown evenly; large marshmallows can brown more quickly and risk burning.
Can you add nuts or a streusel?
Yes—pecans are a popular addition. For a streusel, combine ½ cup flour, ¼ cup rolled oats, ¼ tsp cinnamon, 2 tsp brown sugar, and 4 tbsp melted butter; sprinkle over the sweet potatoes before the marshmallow layer.
Make-ahead tips
You can prepare the sweet potato base ahead and refrigerate for 3–4 days. Hold marshmallows separately and add them just before baking.
What to Serve With Marshmallow Sweet Potato Casserole
- Southern baked ham with pineapple
- Cajun-spiced roasted turkey
- Baked turkey wings
- Lobster mac and cheese or seafood mac and cheese
- Scalloped corn or southern turnip greens
More Sweet Potato Recipes
- Sweet potato cornbread
- Southern candied sweet potatoes
- Purple sweet potato dishes
- Healthy sweet potato pie
- Stovetop candied sweet potatoes
- Mashed sweet potatoes with brown sugar
