Sweet Potato Casserole with Marshmallows
A quiet kitchen test before a family dinner turned into my favorite Sweet Potato Casserole with Marshmallows. When everyone asked for the recipe again, I knew this sweet potato casserole was staying on our table. It has a soft creamy center and a toasted marshmallow layer that feels familiar without being too heavy.
The recipe starts with tender orange sweet potatoes and warm spices, then finishes with a golden topping. If you enjoy sweet potato flavors, try our Maple Sweet Potato Mash for another simple side dish with a similar base. I usually make smaller batches, but this one doubles well when more guests arrive.
This dish works as a holiday side, a family dinner favorite, or part of a weekend meal plan. Among many sweet potato casserole recipes, this version keeps the texture smooth while adding just enough sweetness from the marshmallows.
Why This Recipe Works
Baking sweet potatoes at 375°F before mashing breaks down their fibers and creates a smooth base. Mixing eggs into the warm mash helps the filling set without becoming firm.
The marshmallows go on near the end because 375°F for a short time browns the sugar while protecting the soft center. If you like similar comforting sides, try our Fall Casserole for Dinner for another baked family dish.
Ingredients
- orange sweet potato: Baked until tender and mashed for a smooth creamy filling.
- unsalted butter: Melted into the warm sweet potato mixture for richness.
- brown sugar: Adds caramel sweetness and balances the earthy flavor.
- large eggs: Mixed into the filling to help create a stable texture.
- vanilla extract: Adds a warm sweet aroma to the base.
- ground cinnamon: Provides classic spice flavor throughout the casserole.
- salt: Enhances the sweetness and balances the filling.
- mini marshmallows: Scattered on top for a soft toasted topping.
Kitchen Equipment
- 9×13 ceramic baking dish: A 9×13 ceramic baking dish holds the casserole layer evenly and helps prevent scorching, while a thin pan may brown the edges too quickly.
- Potato masher: A sturdy potato masher breaks down baked sweet potatoes smoothly, while a weak tool can leave unwanted chunks.
How to Make It
Step 1: Mash the softened sweet potatoes
Bake 3 pounds of orange sweet potato at 375°F for 45 to 55 minutes until the flesh is tender, then scoop and mash with a potato masher using firm downward presses. Add 1/2 cup unsalted butter, 1/2 cup brown sugar, 2 large eggs, 1 teaspoon vanilla extract, 1 teaspoon cinnamon, and 1/2 teaspoon salt while folding with a rubber spatula in slow circles. It should smell warm and sweet.
The mixture turns smooth with a few natural orange streaks. You’ll see the butter disappear into the mash. Miss this stage and the filling can stay lumpy.
Bake the sweet potatoes fully before mixing so the starches soften.
Tip: Choose sweet potatoes with deep orange flesh because they create a richer color and smoother texture after baking.
Step 2: Spread the filling into the baking dish
Transfer the sweet potato mixture into a 9×13 ceramic baking dish and spread it evenly at room temperature for 5 minutes using a rubber spatula with smooth sweeping motions. Bake at 350°F for 20 to 25 minutes until the center begins to set and the edges look slightly darker. Keep the layer loose and avoid packing it tightly.
The top will look matte and the filling will hold soft ridges from the spatula. I tried baking the filling at 400°F first and the outside firmed before the middle. This timing keeps the texture balanced.
Bake gently because slow heat prevents a dry center.
Tip: Grease the baking dish with 1 tablespoon butter before adding the filling so portions release more cleanly later.
Step 3: Add the marshmallow topping and brown the surface
Cover the warm sweet potato filling with 3 cups mini marshmallows in an uneven layer, then bake at 375°F for 8 to 10 minutes until the marshmallows puff and turn light golden. Use your fingers to scatter the marshmallows naturally with small gaps instead of making a flat cover. It changes fast.
You’ll notice the marshmallows swell and the edges become lightly toasted. The smell shifts from spice to caramel sweetness. Go past 10 minutes and the sugar can burn.
The short bake melts the topping while keeping the filling creamy.
Tip: Use fresh mini marshmallows from a sealed bag because older ones often dry out and brown unevenly.
Step 4: Serve the finished casserole portion
Rest the casserole at 375°F oven temperature off heat for 10 minutes before serving, then scoop one portion with a wide spoon while keeping the marshmallow layer intact. Move the portion gently so the creamy orange filling and toasted top stay together. (My first batch was served too soon and the center slid apart.
The rest fixed it. ) The final portion shows fluffy filling, melted marshmallow pockets, and uneven golden patches. You’ll smell cinnamon and toasted sugar right away.
Skip the rest and the layers can separate. Resting lets the filling firm without losing moisture.
Tip: Serve within 15 minutes after resting for the best contrast between warm filling and soft toasted marshmallows.
Pro Tips
- Bake the orange sweet potatoes at 375°F until a knife slides in easily, usually 45 to 55 minutes, because fully softened flesh makes a smoother mash.
- Choose small to medium orange sweet potatoes that feel heavy for their size. They usually have better moisture than large dry roots.
- Use a 9×13 ceramic baking dish for this recipe because it spreads the filling evenly and helps avoid thin edges that dry out.
- Prepare the filling up to 24 hours ahead and keep it covered in the fridge, then add the marshmallows right before baking.
- Don’t add marshmallows too early. Adding them only during the final 8 to 10 minutes keeps the topping golden instead of melted away.
- Add 1/2 teaspoon extra cinnamon if you prefer a warmer spice note, but taste the filling before changing the sugar level.
- Let the casserole rest for 10 minutes after baking at 375°F so the soft center holds its shape when served.
- Add 1/2 cup chopped pecans and 1 teaspoon maple extract before baking for a nutty holiday variation with extra crunch.
- Create a lighter version by reducing brown sugar to 1/4 cup and adding 2 tablespoons orange juice for fresh flavor without losing moisture.
- Make a spiced fall version with 1/2 teaspoon nutmeg and 1/4 teaspoon ground ginger mixed into the sweet potato filling.
- For a savory twist, skip the marshmallows and add 1/2 cup shredded sharp cheddar with cracked black pepper before the final bake.
Substitutions & Variations
- unsalted butter: plant-based butter — Use the same 1/2 cup amount for a dairy-free version. The filling will be slightly less rich but keeps a smooth texture if the butter substitute melts well.
- large eggs: flax eggs — Replace 2 large eggs with 2 flax eggs made from 2 tablespoons ground flaxseed and 5 tablespoons water. The casserole will be softer and less custard-like.
- mini marshmallows: dairy-free mini marshmallows — Use the same 3 cups amount if available. The topping texture stays similar, but some brands melt faster, so watch closely after 6 minutes.
- brown sugar: maple syrup — Replace 1/2 cup brown sugar with 1/3 cup maple syrup and reduce other liquid additions if needed. The flavor becomes deeper with a lighter caramel note. For another sweet potato idea, try our Maple Sweet Potato Mash.
- orange sweet potato: sweet potato casserole with canned yams — Use drained canned yams when fresh sweet potatoes are unavailable. The texture becomes softer and sweeter, so reduce the brown sugar slightly if the yams are already syrup-packed.
Storage Instructions
Keep leftovers covered in an airtight container in the fridge for up to 4 days. Freeze the baked sweet potato filling without marshmallows for up to 2 months, wrapped tightly to prevent freezer burn.
Reheat at 350°F for 15 to 20 minutes and add fresh marshmallows during the final minutes if needed. Discard it if you notice sour smells, watery separation, or mold.
Sweet Potato Casserole with Marshmallows
Ingredients
- 3 pounds orange sweet potato Baked until tender and mashed for a smooth creamy filling.
- 1/2 cup unsalted butter Melted into the warm sweet potato mixture for richness.
- 1/2 cup brown sugar Adds caramel sweetness and balances the earthy flavor.
- 2 large large eggs Mixed into the filling to help create a stable texture.
- 1 teaspoon vanilla extract Adds a warm sweet aroma to the base.
- 1 teaspoon ground cinnamon Provides classic spice flavor throughout the casserole.
- 1/2 teaspoon salt Enhances the sweetness and balances the filling.
- 3 cups mini marshmallows Scattered on top for a soft toasted topping.
Instructions
- Bake 3 pounds of orange sweet potato at 375°F for 45 to 55 minutes until the flesh is tender, then scoop and mash with a potato masher using firm downward presses. Add 1/2 cup unsalted butter, 1/2 cup brown sugar, 2 large eggs, 1 teaspoon vanilla extract, 1 teaspoon cinnamon, and 1/2 teaspoon salt while folding with a rubber spatula in slow circles. It should smell warm and sweet. The mixture turns smooth with a few natural orange streaks. You’ll see the butter disappear into the mash. Miss this stage and the filling can stay lumpy. Bake the sweet potatoes fully before mixing so the starches soften.
- Transfer the sweet potato mixture into a 9×13 ceramic baking dish and spread it evenly at room temperature for 5 minutes using a rubber spatula with smooth sweeping motions. Bake at 350°F for 20 to 25 minutes until the center begins to set and the edges look slightly darker. Keep the layer loose and avoid packing it tightly. The top will look matte and the filling will hold soft ridges from the spatula. I tried baking the filling at 400°F first and the outside firmed before the middle. This timing keeps the texture balanced. Bake gently because slow heat prevents a dry center.
- Cover the warm sweet potato filling with 3 cups mini marshmallows in an uneven layer, then bake at 375°F for 8 to 10 minutes until the marshmallows puff and turn light golden. Use your fingers to scatter the marshmallows naturally with small gaps instead of making a flat cover. It changes fast. You’ll notice the marshmallows swell and the edges become lightly toasted. The smell shifts from spice to caramel sweetness. Go past 10 minutes and the sugar can burn. The short bake melts the topping while keeping the filling creamy.
- Rest the casserole at 375°F oven temperature off heat for 10 minutes before serving, then scoop one portion with a wide spoon while keeping the marshmallow layer intact. Move the portion gently so the creamy orange filling and toasted top stay together. (My first batch was served too soon and the center slid apart. The rest fixed it.) The final portion shows fluffy filling, melted marshmallow pockets, and uneven golden patches. You’ll smell cinnamon and toasted sugar right away. Skip the rest and the layers can separate. Resting lets the filling firm without losing moisture.
Notes
Frequently Asked Questions
Yes, prepare the sweet potato filling up to 24 hours ahead and store it covered in the refrigerator. Add the mini marshmallows just before baking at 375°F for 8 to 10 minutes so the topping stays soft and lightly toasted.
Store leftovers in an airtight container or covered baking dish for up to 4 days. Reheat individual portions at 350°F for 15 to 20 minutes until the center feels warm and the marshmallows soften again.
Yes, canned yams work when fresh sweet potatoes are unavailable. Drain them well and reduce the brown sugar by about 2 tablespoons if they contain syrup because the filling can become overly sweet.
A watery casserole usually comes from excess moisture in the sweet potatoes or canned yams. Bake fresh sweet potatoes until tender at 375°F and mash them after steam escapes for about 5 minutes.
Yes, double the ingredients and use two 9×13 baking dishes instead of making one deeper casserole. A thicker layer needs extra baking time and may take 35 to 40 minutes before adding marshmallows.
Freeze the sweet potato filling without marshmallows for up to 2 months in a freezer-safe container. Thaw overnight, bake at 350°F until warm, then add fresh marshmallows for the final topping.
Final Thoughts
After many family dinners, I still remember making this for the first time and wondering if the marshmallow topping would work. Turns out it’s one of those dishes that welcomes beginners and stays forgiving.
You can adjust the sweetness like I did in my first tries and this sweet potato casserole still keeps its charm. If you try this Sweet Potato Casserole with Marshmallows, leave me a comment below.
And if you enjoyed this sweet potato casserole with canned yams style idea, check out our Maple Sweet Potato Mash and other sweet potato casserole recipes for more inspiration. The same batch covers best sweet potato casserole without a single change.
Sweet potato casserole became a popular American holiday side after marshmallows were promoted in recipes during the early 1900s. The sweet topping helped make vegetables feel more like a special treat.
