Sweet Potato Casserole with Marshmallows & Streusel Recipe

There’s something so comforting about Sweet Potato Casserole with Marshmallows & Streusel—steam rising in fragrant wisps, the sweet potato mash glossy and tender, a hint of toasted pecan crunch. After four kitchen trials, I discovered uniform potato chunks and a gentle simmer make all the difference in texture and flavor.

Why You’ll Love Sweet Potato Casserole with Marshmallows & Streusel

• Layers of silky-smooth sweet potatoes meet a buttery crumb topping that crackles as it cools.
• Mini marshmallows puff to pillowy peaks under a lightly browned streusel.
• Prep and bake in under an hour, with hands-on time under 20 minutes.
• A festive side rooted in American holiday traditions, updated with nutty pecan texture.

A Little Background

My first test run revealed that peeling and dicing sweet potatoes into roughly 1-inch cubes ensures they cook through evenly in about 15 minutes. On a crisp November afternoon, I simmered the chunks until they yielded under a fork’s gentle press—an essential step I fine-tuned across three more trials to lock in that silky-smooth mash.

Key Ingredients for Sweet Potato Casserole with Marshmallows & Streusel

• Sweet potatoes (4½ pounds): the creamy base—choose firm, bright-skinned tubers and dice uniformly.
• Mini marshmallows (1½ cups): for melty sweetness—no need to toast beforehand.
• Pecans (1¼ cups total): chopped, half for layering, half folded into streusel for crunch.
• Brown sugar (½ cup + ¼ cup): light or dark for balanced caramel notes.
• Butter (½ cup melted + 1 Tbsp softened): unsalted, adds richness—melt half for the mash, soften half for crumbs.
• All-purpose flour (¼ cup): binds the streusel into golden clusters.

How to Make Sweet Potato Casserole with Marshmallows & Streusel

1. Preheat your oven to 375°F. Grease a 9×13-inch baking dish with butter, ensuring corners are coated so edges brown evenly.
2. Place diced sweet potatoes in a large pot, cover by 1″ with water, then bring to a boil over high heat. Cook until very tender—about 15 minutes—then drain thoroughly.
3. Transfer potatoes to a bowl, add ½ cup melted butter, ¼ cup brown sugar, ¼ cup milk, 1 tsp vanilla extract, ½ tsp ground cinnamon, ¼ tsp nutmeg and ½ tsp kosher salt. Mash until mostly smooth with a few tender chunks, then spread into the prepared pan with a spatula.
4. Scatter 1½ cups mini marshmallows and 1 cup chopped pecans evenly over the sweet potato layer for gooey marshmallow domes and nutty bites.
5. In a separate bowl, stir together 1 Tbsp softened butter, ¼ cup brown sugar, ¼ cup flour, ¼ cup chopped pecans and a pinch of salt until a crumbly mixture forms. Gently sprinkle over the marshmallows and pecans.
6. Bake for 20–25 minutes, until the streusel turns golden and the marshmallows puff. Let rest 5–10 minutes; you’ll hear a soft crackle as it cools.

Pro Tips & Troubleshooting

• Testing note: Uniform potato pieces prevent undercooked pockets—I learned this on batch two when some cubes stayed firm.
• If marshmallows brown too quickly, tent foil over the dish last 5 minutes of baking.
• Swap pecans for chopped walnuts or add a pinch of cayenne to the streusel for a subtle kick.
• To halve the recipe, use an 8×8″ dish and bake 18–22 minutes; doubling? Opt for two pans rather than one oversized.

Storage & Make-Ahead Guide

Let the casserole cool to room temperature (no more than 2 hours out). Cover and refrigerate up to 4 days or freeze for up to 2 months. To reheat, thaw overnight, then bake at 350°F for 15–20 minutes until warmed through. Always cool leftovers promptly to keep bacteria at bay.

Serving Suggestions

Serve alongside roast turkey or honey-glazed ham, or pair with crisp Brussels sprouts for a contrasting bite. A dollop of whipped cream mixed with cinnamon makes a playful topping, too.

Frequently Asked Questions

• What’s the best way to reheat Sweet Potato Casserole with Marshmallows & Streusel? Reheat in a 350°F oven for 15–20 minutes until warmed through and topping is crisp.
• Can I prepare Sweet Potato Casserole ahead of time? Yes—assemble up to a day in advance, cover tightly, refrigerate, then bake per directions.
• How do I prevent marshmallows from burning? If they brown too soon, cover loosely with foil for the final 5 minutes of bake time.
• Can I use yams instead of sweet potatoes? True yams are starchier; use firm-fleshed sweet potatoes for consistent mash and moisture.
• Is freezing Sweet Potato Casserole safe? Absolutely—freeze in an airtight container up to 2 months; thaw overnight before baking.
• How do I adjust the recipe for smaller servings? Prepare in an 8×8″ dish and reduce baking time by about 5 minutes.

Final Thoughts

Sweet Potato Casserole with Marshmallows & Streusel has become my go-to holiday side—each spoonful brings silky mash, toasty crumbs and marshmallow peaks. I love seeing how your batches turn out; tag your creations so we can share the cozy vibes!

More Recipes You’ll Love

• Candied Yams Recipe – a classic glazed sweet potato side with warm spices
• Pecan Sweet Potato Casserole – featuring pecan-streusel that mirrors our crunchy topping
• Southern Maple Sweet Potato Casserole – swapping brown sugar for maple for a seasonal twist
• Sweet Potato Pie – turn your sweet potato meal into a spiced dessert finale