Creamy, cozy, and just sweet enough, this Sweet Potato Casserole with Marshmallows brings that nostalgic, toasty topping and velvety filling to your holiday table. It is simple to make, endlessly comforting, and always the first dish to disappear.
Why You’ll Love This Sweet Potato Casserole with Marshmallows
- Ultra creamy filling with warm spices and a golden, toasty marshmallow crown.
- Make-ahead friendly so holiday hosting feels calm and enjoyable.
- Balanced sweetness that complements savory mains beautifully.
- Easy to adapt for dairy-free, nut-free, or egg-free diets.
Sweet Potato Casserole with Marshmallows Ingredients & Substitutions
- 3 lb sweet potatoes (about 4 large)
- 4 tbsp unsalted butter, melted (sub coconut oil or vegan butter)
- 1/3 cup light or dark brown sugar (sub maple syrup or coconut sugar)
- 1/3 cup milk or heavy cream (sub canned coconut milk for dairy-free)
- 1 tsp pure vanilla extract
- 1 tsp ground cinnamon
- 1/4 tsp ground nutmeg
- 1/2 tsp kosher salt
- 1/4 tsp ground ginger, optional
- 1 large egg, lightly beaten, optional for a slightly firmer set
- 3 cups mini marshmallows (use vegan marshmallows if needed)
- Optional add-in: 1/2 cup chopped pecans for a little crunch beneath the marshmallows
Simple swaps: Use canned sweet potatoes in juice, well drained, and reduce brown sugar to 2 tbsp. For refined sugar free, sweeten with 2 to 3 tbsp maple syrup. Skip the egg for a softer, scoopable texture.
Step-by-Step Instructions to Make Sweet Potato Casserole with Marshmallows
Step 1: Roast the sweet potatoes
Preheat oven to 400°F. Scrub and pierce sweet potatoes with a fork. Place on a foil-lined sheet and roast 45 to 60 minutes until very tender. Let cool until safe to handle. Tip: You can boil peeled chunks in salted water for 20 to 25 minutes, but roasting concentrates flavor and avoids excess moisture.
Step 2: Peel and mash
Reduce oven to 350°F. Peel the skins and transfer flesh to a large bowl. Mash until smooth and creamy. If the potatoes seem watery, set the mash over low heat in a pot for 2 to 3 minutes to steam off extra moisture.
Step 3: Mix the filling
Stir in melted butter, brown sugar, milk, vanilla, cinnamon, nutmeg, salt, and ginger if using. Taste and adjust sweetness. If using the egg, let the mixture cool to warm, then whisk in the egg to avoid scrambling.
Step 4: Assemble and bake
Grease a 9×13 baking dish. Spread the sweet potato mixture into the dish and smooth the top. Bake at 350°F for 20 to 25 minutes until hot and slightly puffed around the edges.
Step 5: Add marshmallows and toast
Top evenly with mini marshmallows. Return to the oven for 8 to 10 minutes until the marshmallows are soft and golden. For extra color, broil for 30 to 60 seconds, watching closely. Let rest 10 minutes before serving.
Tips for Success
- Pick sweet potatoes that feel heavy for their size and have vibrant orange flesh.
- Roast instead of boil for deeper flavor and a thicker, silkier mash.
- Add the egg only when the mixture is warm, not hot, to prevent curdling.
- Toast the marshmallows at the end to keep them gooey, not dried out.
- For dairy-free, use coconut milk and vegan marshmallows. For nut-free, simply skip pecans.
Variations of Sweet Potato Casserole with Marshmallows
- Maple Bourbon: Replace half the brown sugar with maple syrup and add 1 tbsp bourbon.
- Pecan Praline Swap: Skip marshmallows and top with a pecan crumble of 1/2 cup brown sugar, 1/2 cup flour, 1 cup chopped pecans, and 5 tbsp melted butter.
- Coconut Kissed: Stir in 1/2 cup toasted coconut and use coconut milk. Top with marshmallows plus a sprinkle of coconut.
- Lightly Savory: Reduce sugar to 2 tbsp, add a pinch of smoked paprika, and finish with flaky salt under the marshmallows.
Serving Suggestions: What to Pair with Sweet Potato Casserole
- Roast turkey, holiday ham, or herb-roasted chicken.
- Bright sides like garlicky green beans, shaved Brussels sprouts salad, or cranberry sauce.
- Sips: spiced apple cider, lightly oaked Chardonnay, or unsweet iced tea with lemon.
Storage & Reheating Instructions
- Refrigerate: Cover leftovers and refrigerate up to 4 days.
- Reheat: Bake at 325°F until warmed through, about 15 to 20 minutes. If the marshmallows are already toasted, tent with foil to prevent over-browning.
- Freeze: Best frozen without the marshmallow topping. Cool the baked filling, wrap tightly, and freeze up to 2 months. Thaw overnight, reheat, then add marshmallows and toast.
- Make Ahead: Assemble the filling in the dish, cover, and refrigerate up to 2 days. Bake, then add marshmallows and toast before serving.
Memories Made Around the Table
Every year I set this on the table and watch the marshmallows gently collapse into a golden blanket. Someone always sneaks a spoonful before dinner, and I always smile and pretend not to notice.
FAQs
Can I make this ahead? Yes. Assemble the filling in the baking dish, cover, and refrigerate up to 2 days. Bake, then add and toast the marshmallows just before serving.
Can I use canned sweet potatoes? Absolutely. Drain well and reduce brown sugar to 2 tbsp since canned sweet potatoes are already sweet.
How do I keep the marshmallows from burning? Add them at the end and toast briefly. If they brown too fast, tent the dish loosely with foil.
Is the egg necessary? No. It helps the casserole set slightly, but you can skip it for a soft, scoopable texture.
Can I boil the potatoes instead of roasting? Yes. Boil peeled chunks 20 to 25 minutes until tender, then drain very well to prevent a watery filling.
Final Thoughts
This Sweet Potato Casserole with Marshmallows delivers buttery, spiced comfort with a festive, gooey finish. Make it once, and it will earn a permanent place at your holiday table.
Sweet Potato Casserole with Marshmallows
Equipment
- 1 9x13 inch baking dish greased
- 1 Baking Sheet lined with foil
- 1 Large bowl
- 1 potato masher or hand mixer
- 1 Aluminum foil (optional) for lining/tenting
Ingredients
Filling
- 3 lb sweet potatoes about 4 large
- 4 tbsp unsalted butter melted (sub coconut oil or vegan butter)
- 0.33 cup light or dark brown sugar packed (sub maple syrup or coconut sugar)
- 0.33 cup milk or heavy cream sub canned coconut milk for dairy-free
- 1 tsp pure vanilla extract
- 1 tsp ground cinnamon
- 0.25 tsp ground nutmeg
- 0.5 tsp kosher salt
- 0.25 tsp ground ginger optional
- 1 large egg lightly beaten, optional for a slightly firmer set
- 0.5 cup chopped pecans optional add-in for crunch
Topping
- 3 cup mini marshmallows use vegan marshmallows if needed
Instructions
Steps
- Preheat oven to 400°F. Scrub and pierce sweet potatoes with a fork. Place on a foil-lined sheet and roast 45 to 60 minutes until very tender. Let cool until safe to handle. Tip: You can boil peeled chunks in salted water for 20 to 25 minutes, but roasting concentrates flavor and avoids excess moisture.
- Reduce oven to 350°F. Peel the skins and transfer flesh to a large bowl. Mash until smooth and creamy. If the potatoes seem watery, set the mash over low heat in a pot for 2 to 3 minutes to steam off extra moisture.
- Stir in melted butter, brown sugar, milk, vanilla, cinnamon, nutmeg, salt, and ginger if using. Taste and adjust sweetness. If using the egg, let the mixture cool to warm, then whisk in the egg to avoid scrambling. Fold in pecans if using.
- Grease a 9x13 baking dish. Spread the sweet potato mixture into the dish and smooth the top. Bake at 350°F for 20 to 25 minutes until hot and slightly puffed around the edges.
- Top evenly with mini marshmallows. Return to the oven for 8 to 10 minutes until the marshmallows are soft and golden. For extra color, broil for 30 to 60 seconds, watching closely. Let rest 10 minutes before serving.
Storage & Reheating
- Refrigerate leftovers up to 4 days. Reheat at 325°F until warmed through, about 15 to 20 minutes (tent if marshmallows brown too fast). For freezing, bake filling without marshmallows, cool, wrap, and freeze up to 2 months; thaw, reheat, then add and toast marshmallows. For make-ahead, assemble filling in the dish, cover, and refrigerate up to 2 days; bake, then add and toast marshmallows before serving.