Old Fashioned Sweet Potato Casserole with Marshmallows

There’s something irresistibly comforting about a warm dish of Old Fashioned Sweet Potato Casserole with Marshmallows. Think creamy, spiced sweet potatoes layered beneath a blanket of gooey marshmallows and a crunchy pecan streusel—simple, nostalgic, and endlessly satisfying. This recipe keeps the classic flavors you love while giving you clear, friendly steps so you can make it with confidence.

Why You’ll Adore This Old Fashioned Sweet Potato Casserole with Marshmallows

This casserole marries smooth, lightly spiced mashed sweet potatoes with a sweet, toasted marshmallow topping. It’s the kind of dish that brings comfort and a little ceremony—perfect for holidays, potlucks, or any meal when you want something warm and homey. The creaminess of the potatoes, the caramel notes from brown sugar, and the crunch from pecans (if you add them) make each bite a delightful contrast of textures and flavors.

Ingredients for Old Fashioned Sweet Potato Casserole with Marshmallows

• Sweet potatoes (2 lb) — The heart of the dish. Bake or boil until very tender so they mash silky smooth.
• Unsalted butter (1/3 cup) — Adds richness and helps create a luscious consistency.
• Brown sugar (1/3 cup) — Sweetens the mash with a deep, caramel flavor; more or less to taste.
• Ground cinnamon (1 tsp) — Brings warm spice notes that pair beautifully with sweet potato.
• Ground nutmeg (1/4 tsp) — A little goes a long way to deepen the flavor profile.
• Salt (1/2 tsp) — Balances and enhances the sweetness.
• Vanilla extract (1 tsp) — Lifts and rounds the overall flavor.
• Milk or cream (1/4 cup) — Smooths the mash; use cream for extra richness or milk for a lighter result.
• Large egg (1) — Helps bind the filling so slices hold together when scooped.
• Mini marshmallows (1 cup) — The classic topping—gooey, sweet, and toasty when baked.
• Pecans, chopped (1/2 cup, optional) — Adds a toasty crunch and nutty flavor to the streusel.
• All-purpose flour (1/4 cup) — Used in the streusel to form crumbs with the sugar and butter.
• Brown sugar for streusel (2 tbsp) — Helps caramelize the streusel topping.
• Salt for streusel (pinch) — Balances the sweet topping and brings out nutty notes.

Step-by-Step Guide to Making Old Fashioned Sweet Potato Casserole with Marshmallows

1. Preheat your oven to 350°F (175°C). Lightly grease a 9x9-inch baking dish and set aside.
2. Cook the sweet potatoes. You can either bake them whole at 400°F until very tender (45–60 minutes) or peel, cube and boil until fork-tender (about 15–20 minutes). Baking concentrates flavor; boiling is faster. Drain well if boiled.
3. Mash the sweet potatoes. Place the hot potatoes in a large bowl and mash until mostly smooth. Add the butter, brown sugar, cinnamon, nutmeg, salt, vanilla, milk, and the egg. Stir until everything is combined and the mixture is creamy. Taste and adjust seasoning—add a little more sugar if you prefer it sweeter.
4. Transfer to the baking dish. Spread the sweet potato mixture evenly in the prepared dish and smooth the top with a spatula so it bakes uniformly.
5. Make the streusel (optional but lovely). Mix chopped pecans, flour, 2 tablespoons brown sugar, a pinch of salt and 2 tablespoons melted butter in a small bowl. Work it with a fork until coarse crumbs form. Scatter the streusel evenly over the sweet potatoes.
6. Top with marshmallows. Sprinkle mini marshmallows across the top—place them on top of the streusel if you used it, or directly on the sweet potato surface.
7. Bake the casserole. Place the dish in the preheated oven for 20–25 minutes, until the filling is hot and the marshmallows are puffed and golden. If the marshmallows need extra color, broil for 1–2 minutes while watching closely so they don’t burn.
8. Rest and serve. Let the casserole sit for 5–10 minutes to set slightly—this makes it easier to serve. Scoop onto plates and enjoy warm.

Timing & Preparation Details

• Active prep: ~15 minutes (mashing, mixing, topping).
• Cook time for sweet potatoes: 15–20 minutes boiling or 45–60 minutes baking, depending on method.
• Bake: 20–25 minutes until heated through and marshmallows are golden.
• Total time: ~50 minutes to 1 hour 30 minutes, depending on sweet potato cooking method.
• Ready to enjoy: Best served warm, right after a 5–10 minute rest so the casserole holds its shape.

Nutritional Snapshot

The following approximate nutrition is per serving (recipe yields about 4 servings):

• Calories: 460 kcal
• Protein: 5 g
• Carbohydrates: 62 g (including ~30 g sugar)
• Fat: 21 g (saturated fat ~9 g)
• Fiber: 5 g
• Sodium: ~320 mg

Note: These values are estimates and will vary based on exact ingredients and serving size.

Frequently Asked Questions

Can I make this casserole ahead of time?

Yes. Prepare the sweet potato mixture and streusel, assemble in the dish, cover and refrigerate up to 24 hours. Add marshmallows just before baking, then bake as directed—add a few extra minutes if starting cold.

How can I avoid burnt marshmallows?

Watch closely during broiling: marshmallows can go from golden to burnt in seconds. If you prefer, bake until marshmallows are soft and lightly golden without using the broiler, or place a piece of foil loosely over the dish if the marshmallows brown too quickly while the filling still needs time to heat through.

Can I make a nut-free version?

Absolutely. Omit the pecans and either skip the streusel or make a simple oat-based topping (rolled oats, butter, brown sugar) if you want crunch without nuts.

There you have it: a timeless Old Fashioned Sweet Potato Casserole with Marshmallows that’s easy to make and endlessly comforting. Whether it’s a holiday centerpiece or a cozy side for weeknight dinner, this recipe invites warm memories and happy bellies. If you’d like a lighter version, tips for scaling the recipe, or a vegan adaptation, tell me which direction you want and I’ll help you tweak it.