This Sweet Potato Casserole recipe blends creamy mashed sweet potatoes with warm cinnamon, brown sugar, and butter, then finishes with your choice of a crunchy pecan streusel or gooey toasted marshmallows. The dish combines sweet and savory flavors in every bite, using simple boiling-and-mashing techniques for perfectly smooth potatoes. Ready in about an hour, this classic holiday side is easy to prepare ahead and always a crowd favorite.
Peel sweet potatoes and chop them into 4 pieces. Place sweet potato chunks into a pot and fill it with water, just enough to cover the potatoes.
Bring water to boil and cook potatoes until fork-tender. Strain all the water out of the pot and let potatoes cool for a few minutes.
Add butter, eggs, milk, brown sugar, and vanilla extract and mash it all together using a potato masher.
Grease a 9×9 casserole pan with some butter all over the bottom and up the sides. Spread potato mixture evenly in the pan.
Preheat the oven to 350°F.
Pecan Crumble Topping:
Combine flour, brown sugar, cinnamon, and chopped pecans in a mixing bowl and mix until all evenly incorporated.
Pour in melted butter while stirring with a fork. Continue to cut and fold with a fork until coarse crumbs form. The topping should look like crumbs, not paste.
Spread the pecan topping over sweet potatoes evenly and bake the casserole for 40-45 minutes.
Marshmallow Topping Option:
For the marshmallow topping, you can choose to add marshmallows on top of the crunchy pecan topping or just stick to simple pecan and marshmallows.
Spread pecans (or pecan crunch topping) over the sweet potato filling and bake for about 30 minutes.
Take the casserole out and spread marshmallows over the top. (If you want to get super creative, sprinkle a little bit of coarse salt on top as well.)
Bake for another 10-15 minutes, until the marshmallows are golden brown.
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Notes
Nutrition NOTE: nutrition is calculated for Sweet Potato Casserole with Pecan Crunch Topping.
Gluten free - to make this casserole gluten free, use gluten free all purpose flour in the pecan crumble topping.
Make Ahead (full instructions in post!): You can prepare the filling 1 day in advance. Spread it in the baking dish, cover tightly, and refrigerate. Add the topping right before baking.
Storage: Leftovers keep well in the refrigerator for 3–4 days covered air-tight. Reheat covered at 325°F until warmed through.
Freezing: Freeze unbaked casserole (without the topping) up to 3 months. Thaw overnight in the refrigerator, add topping, and bake as directed.
Reheating: Reheat baked casserole at 325°F for 20–25 minutes. If using marshmallows, add a fresh handful at the end so they toast nicely.