There is one dish that instantly signals the start of the holiday season in my home: the Classic Sweet Potato Casserole. This isn’t just a side dish; it’s a nostalgic hug in a baking dish. The combination of velvety, whipped sweet potatoes and that iconic, gooey toasted marshmallow blanket is a tradition that never goes out of style.
My secret to making this the best version you’ve ever tasted? It’s all about the texture. By steaming off the potatoes after boiling and adding a touch of heavy cream, we achieve a filling that is light, fluffy, and perfectly spiced with cinnamon and nutmeg. Whether it’s Thanksgiving, a potluck, or a cozy Sunday dinner, this casserole is always the first one to disappear!

Why You’ll Love This Recipe
- Perfect Texture: Fluffy whipped potatoes with zero “wateriness.”
- Toasted Perfection: A crackly, golden marshmallow topping that provides that satisfying stretch.
- Make-Ahead Magic: You can prep the base up to two days early, making your holiday morning much smoother.
- Crowd Favorite: It strikes the perfect balance between sweet and salty, making it a hit with both kids and adults.
Recipe Card Info
- Prep Time: 20 minutes
- Cook Time: 50 minutes
- Total Time: 1 hour 10 minutes
- Servings: 10
- Difficulty: Easy
Ingredients
The Sweet Potato Filling:
- 4 large sweet potatoes (peeled and cut into chunks)
- 1/2 cup unsalted butter, melted
- 1/2 cup brown sugar, packed
- 1/4 cup heavy whipping cream
- 2 large eggs, lightly beaten
- 1 tsp pure vanilla extract
- 1 tsp ground cinnamon
- 1/2 tsp ground nutmeg
- 1/2 tsp salt
The Topping:
- 3 cups mini marshmallows

Instructions
- Prep: Preheat your oven to 350°F (175°C). Lightly butter a 9×13 inch glass baking dish.
- Boil: Place sweet potato chunks in a large pot of salted cold water. Bring to a boil and cook for 15–18 minutes until fork-tender.
- Steam Dry: Drain the potatoes well and return them to the hot pot for 2–3 minutes. This allows excess moisture to evaporate, ensuring a thick, rich custard.
- Whisk Custard: In a medium bowl, whisk together melted butter, brown sugar, heavy cream, eggs, vanilla, cinnamon, nutmeg, and salt until smooth.
- Mash & Combine: Add the custard mixture to the warm potatoes and mash until smooth (or leave a few rustic bits if you prefer).
- Bake Base: Spread the mixture into the prepared dish. Bake for 20–25 minutes until the edges are set and lightly puffed.
- Toast: Remove from the oven and scatter marshmallows in an even layer. Bake for another 5–8 minutes until golden. For extra color, broil for 30–60 seconds (watch closely!).
- Rest: Let it sit for 10 minutes before serving so it sets up for cleaner slices.
Chef’s Tips for Success
- Tip 1 (Avoid Watery Casserole): Always return your drained potatoes to the hot pot to “steam dry.” This simple step is the difference between a watery mess and a velvety masterpiece.
- Tip 2 (Brown the Butter): For a deeper, toffee-like flavor, brown your butter in a skillet before adding it to the custard.
- Tip 3 (Egg Safety): Let the mashed potatoes cool for a couple of minutes before adding the egg mixture to prevent the eggs from scrambling.
Encouraging Conclusion
This Classic Sweet Potato Casserole is more than just a recipe; it’s a centerpiece of memories. The way the warm cinnamon spices play off the toasted marshmallows is pure comfort food at its best.