Sweet Potato Casserole with Marshmallows & Streusel
This Sweet Potato Casserole with Marshmallow-Pecan Streusel features creamy mashed sweet potatoes topped with mini marshmallows and a crunchy streusel made with pecans, brown sugar, flour, and butter.
Ingredients
Sweet Potato Mixture
- 4.5 pounds sweet potatoes peeled and cut into 1-inch chunks
- 0.5 cup unsalted butter melted
- 0.25 cup whole milk
- 1 teaspoon pure vanilla extract
- 0.5 cup brown sugar lightly packed
- 1 teaspoon cinnamon
- 0.25 teaspoon nutmeg
- 0.5 teaspoon salt
- 4 teaspoons water
Topping & Streusel
- 1.5 cups mini marshmallows
- 1.25 cups pecans divided (¾ cup for topping; ½ cup finely chopped for streusel)
- 0.25 cup brown sugar lightly packed
- 0.25 cup all-purpose flour
- 1 tablespoon unsalted butter softened
Instructions
Sweet Potato Mixture
- Place sweet potatoes in a large pot and cover with water by 1 inch. Bring to a boil over high heat and cook until very tender, about 15 minutes.
- Drain the potatoes and return them to the pot off the heat. Stir in melted butter, milk, vanilla, brown sugar, cinnamon, nutmeg, salt, and water. Mash until mostly smooth but with a few lumps remaining.
- Preheat oven to 375°F and grease a 9×13-inch baking dish. Spread mashed sweet potatoes evenly into the prepared dish.
Topping & Bake
- Sprinkle mini marshmallows and ¾ cup chopped pecans over the sweet potato layer.
- In a bowl, combine brown sugar, flour, finely chopped pecans, and softened butter until crumbly. Sprinkle this streusel mixture over the marshmallows.
- Bake for 20 to 25 minutes, until marshmallows are puffed and the streusel is golden brown.
- Let the casserole rest for 5 minutes before serving.
Notes
Leftover casserole can be refrigerated for up to 4 days or frozen for up to 2 months. To reheat, thaw overnight then bake at 350°F for 15–20 minutes until warmed through.
Make ahead by assembling the casserole the day before; cover and refrigerate, then bake as directed. Bring to room temperature before baking for even cooking.
Nutrition
Serving: 1servingCalories: 340kcalCarbohydrates: 46g
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