Sweet potato casserole with marshmallows is a classic holiday side dish that delivers the perfect combination of creamy, spiced sweet potatoes and a golden, toasted marshmallow topping. It is warm, comforting, and always one of the first things to disappear from the table.

This casserole is easy enough to pull together on a busy holiday morning and can be ready in about an hour from start to finish. The sweet potato base is smooth and lightly sweetened, the brown sugar crumble adds a little crunch, and the marshmallow topping takes it over the top. It works just as well for Thanksgiving dinner as it does for a casual fall weeknight meal.
If you are planning a full holiday spread, check out these Thanksgiving desserts to round out the menu, or browse these Friendsgiving side dishes for even more inspiration.
If you are hosting Thanksgiving this year, the Thanksgiving Find Someone Who game is a fun way to keep guests entertained while dinner finishes up. It is a printable icebreaker game that works for all ages and takes zero prep beyond printing.

Ingredients
- Sweet potatoes
- Eggs
- Granulated sugar
- Milk
- Butter
- Vanilla
- Brown sugar
- Flour
- Mini marshmallows
See recipe card for quantities.
Instructions
Preparation: Peel and cut the sweet potatoes into 1-inch cubes. Preheat the oven to 325 degrees Fahrenheit and grease a 9x13-inch casserole dish.

Step one: Add the sweet potato cubes to a large saucepan and cover with water. Cook over medium-high heat for 12 to 15 minutes until the potatoes are tender when pierced with a fork. Drain and mash until smooth.

Step two: Transfer the mashed sweet potatoes to a large mixing bowl. Add the eggs one at a time, mixing after each addition.

Step three: Mix in the granulated sugar, milk, butter, and vanilla until the mixture is smooth and well combined. Pour into the prepared casserole dish.

Step four: In a small bowl, combine the brown sugar and flour. Cut in the softened butter with a fork until the mixture forms small clumps. Sprinkle evenly over the sweet potato layer.

Step five: Bake for 30 minutes until the topping is set and lightly golden.

Step six: Remove the casserole from the oven and switch the oven to broil. Spread the mini marshmallows in a single layer over the top. Return to the oven and broil for 1 to 2 minutes until the marshmallows are lightly toasted. Watch closely so they do not burn.
Step seven: Remove from the oven and let the casserole rest for 5 minutes before serving.
Hint: Keep a close eye on the marshmallows under the broiler - they can go from perfectly toasted to burned in under a minute.
Recipe Tips for Success
- Make sure your sweet potatoes are fully tender before mashing - undercooked potatoes will leave lumps in the filling that are hard to smooth out later.
- Softened butter in both the filling and the crumble topping is important. Cold butter will not incorporate properly into either.
- Let the casserole set for the full 5 minutes after coming out of the oven before serving - it firms up slightly and is much easier to scoop.
- If you want to get ahead, you can assemble the casserole through the crumble topping the night before, refrigerate it, and add the marshmallows right before baking.
Storage
Store leftover sweet potato casserole in an airtight container in the refrigerator for up to 4 days. Reheat in the oven at 325 degrees or in the microwave until warmed through. The marshmallow topping will not re-toast after storing, but the casserole reheats well. You can also freeze the casserole before adding the marshmallow topping for up to 2 months - thaw overnight in the fridge before baking and topping.
Complete the Occasion

Easy Sweet Potato Casserole with Marshmallows
Ingredients
- 4 cups Sweet Potatoes cubed + peeled
- 2 Eggs
- ½ cups Granulated sugar
- ½ cup Milk
- 4 tablespoon butter softened
- ½ teaspoon vanilla
For the topping
- ½ cup brown sugar
- ⅓ cup flour
- 3 tablespoon butter softened
- 3 cups Marshmallows mini
Instructions
- Peel and cut sweet potatoes into 1-inch cubes. Preheat oven to 325 degrees Fahrenheit and grease a 9x13-inch casserole dish.
- Add sweet potato cubes to a large saucepan, cover with water, and cook over medium-high heat for 12 to 15 minutes until tender. Drain and mash until smooth.
- Transfer mashed sweet potatoes to a large mixing bowl. Add eggs one at a time, mixing after each addition.
- Mix in granulated sugar, milk, butter, and vanilla until smooth and well combined. Pour into the prepared casserole dish.
- In a small bowl, combine brown sugar and flour. Cut in softened butter with a fork until small clumps form. Sprinkle evenly over the sweet potato layer.
- Bake for 30 minutes until the topping is set and lightly golden.
- Switch oven to broil. Spread mini marshmallows in a single layer over the top. Broil for 1 to 2 minutes until lightly toasted, watching closely.
- Remove from oven and let rest for 5 minutes before serving.
Notes
Store in an airtight container in the refrigerator for up to 4 days. Reheat in the oven at 325 degrees or in the microwave. To freeze, assemble without the marshmallow topping and freeze for up to 2 months. Thaw overnight in the fridge before baking and topping. **Recipe Tips**
* Cook sweet potatoes until fully tender before mashing to avoid lumps in the filling.
* Use softened butter in both the filling and the crumble — cold butter will not incorporate properly.
* Let the casserole rest for 5 minutes after baking before scooping.
* Assemble through the crumble topping the night before and refrigerate — add marshmallows right before baking.
Nutrition
Nutrition information provided is just an estimate and may vary based on specific ingredients used.





