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5 from 6 votes

Best Sweet Potato Casserole with Marshmallows

This easy and rich Sweet Potato Casserole with Marshmallows and Pecans has a creamy base topped with crunchy pecans and gooey marshmallow topping, making a comforting and delicious gluten-free side for the Holidays.
Course:Side Dish
Keywords:pecans, sweet potato casserole with marshmallows
Prep Time 20 minutes
Cook Time 35 minutes
Total Time 55 minutes
Servings 12 people
Calories324.1 kcal
Cost $ 0.75 per person


  • 1 Baking dish 9x13-inch
  • 1 pot or microwave-safe dish
  • 1 Mixing bowl
  • 1 potato masher
  • 1 stovetop or microwave


For the Mashed Sweet Potato Base:

  • 3 pounds sweet potatoes washed (about 3-4 large sweet potatoes)
  • 4 tablespoons unsalted butter melted (for making it dairy-free, use dairy-free butter or coconut oil)
  • cup half-and-half or whole milk which is full-fat. NOTE: To make it dairy-free, replace it with unsweetened soy milk or almond milk but you may have to reduce the amount of liquid slightly to not make your mashed sweet potato base watery. A full-fat liquid helps with a thick consistency and a richer flavor.
  • ½ cup light brown sugar Use Brown Swerve for a low-carb or sugar-free dish!
  • 1 teaspoon cinnamon
  • ¼ teaspoon ground nutmeg optional
  • 2 large eggs lightly beaten
  • 1 teaspoon pure vanilla extract
  • ½ teaspoon table salt

For the Topping:

  • ½ cup light brown sugar or Brown Swerve to make it sugar-free or low-carb.
  • ¾ cup oat flour , certified gluten-free. If you don't have oat flour you can make your own by grinding rolled oats in a food processor until obtaining a flour texture. NOTE: If you aren't a celiac, you may replace oat flour with ½ cup of all-purpose flour.
  • ¾ teaspoon cinnamon
  • Pinch table salt
  • 6 tablespoons unsalted butter melted (you may use coconut oil if you prefer to make it dairy-free)
  • 1 ¼ cups chopped pecans for a nut-free casserole, use sunflower seeds instead
  • 2 cups miniature marshmallows you may replace them with the toasted meringue topping below. Or for a low-carb/sugar-free version, use sugar-free marshmallows.

Alternative Topping (Toasted Meringue):

  • 2 eggs separated (yolks from whites)
  • teaspoon cream of tartar
  • ½ cup powdered sugar


  • COOK THE SWEET POTATOES: You can cook them either in the microwave or boil them.
  • To Microwave: Prick the sweet potatoes all over with a fork and place them in a microwave-safe dish. Cook them on full power for about 8-12 minutes (depending on the microwave potency) or until they turn out soft. Then, peel them by gently scrubbing the peel with a pairing knife. Alternatively, cut them lengthwise and scoop all the flesh out of the peel using a spoon or cookie scoop. Just be careful to avoid burning your hands!
  • To Boil: Peel them first, cut them into 1-inch chunks, and place them into a pot filled with cold water (never boiling water; otherwise they won't cook evenly). Bring to a boil and let cook for about 12-15 minutes or until soft. Drain!
  • Meanwhile, preheat the oven to 375º F. Grease a 9x13-inch baking dish with cooking spray or butter.
  • MASH: Using a potato masher, mash the sweet potatoes and stir in melted butter, half-and-half, brown sugar, spices, eggs, vanilla, and salt until creamy and smooth.
  • Transfer the mixture to the prepared baking dish and smooth it out evenly using a rubber spatula.
  • PREPARE THE PECAN TOPPING: In a medium bowl, combine the brown sugar, oat flour, cinnamon, salt, melted butter, and chopped pecans. Mix them well together with a fork or using your hands until combined. Sprinkle over the top of the mashed sweet potatoes.
  • BAKE: Bake the sweet potato casserole until heated all the way through and the topping begins to brown, about  25-30 minutes. Remove it from the oven and sprinkle it with the marshmallows.
  • BROIL THE MASHMALLOWS: Set the oven to broil, then place the baking dish about 6-8 inches away from the top broiler heating source. Let it broil just long enough for the marshmallows to toast on top without burning. TIP: Watch it carefully!
  • Serve it right away and enjoy!
  • OR TOP WITH THE TOASTED MERINGUE TOPPING INSTEAD: Alternatively, If you prefer a toasted meringue topping instead of a marshmallow topping, beat the egg whites with cream of tartar in the bowl of a mixer until foamy, about 1-2 minutes. Add powdered sugar and beat again until stiff, about 1-2 minutes. Increase heat to 400 degrees F. Remove the baked sweet potato casserole from the oven, spoon the meringue on top, and bake on the top rack of the oven for an additional 6-7 minutes or until the meringue is golden brown. Serve immediately!

Recipe Notes

The nutritional facts were calculated using unsweetened soy milk, erythritol, and sugar-free marshmallows. The meringue topping was not included in the calculation because it is optional and alternative. 
How to Store
  • Fridge: Store leftovers in an airtight container for up to 3-4 days. 
  • Freezer: Store sweet potato casserole (without marshmallows or meringue topping), unbaked or baked, and then completely cool, in an airtight container in the freezer for up to 3 months. Thaw in the fridge overnight!
  • To reheat, cover it and reheat in the microwave just until heated through.


Calories: 324.1kcal | Carbohydrates: 46.5g | Protein: 5.4g | Fat: 19.2g | Saturated Fat: 7.1g | Polyunsaturated Fat: 3.3g | Monounsaturated Fat: 7.6g | Trans Fat: 0.4g | Cholesterol: 52.4mg | Sodium: 256.2mg | Potassium: 479.5mg | Fiber: 5.2g | Sugar: 5.4g | Vitamin A: 16440.2IU | Vitamin C: 2.9mg | Calcium: 64.5mg | Iron: 1.5mg

** Nutrition labels on easyanddelish.com are for educational purposes only. This info is provided as a courtesy and is only an estimate, since the nutrition content of recipes can vary based on ingredient brand or source, portion sizes, recipe changes/variations, and other factors. We suggest making your own calculations using your preferred calculator, based on which ingredients you use, or consulting with a registered dietitian to determine nutritional values more precisely.

Please note that health-focused and diet information provided on easyanddelish.com is for educational purposes and does not constitute medical advice, nor is it intended to diagnose, treat, cure, or prevent disease. Consult with your doctor or other qualified health professional prior to initiating any significant change in your diet or exercise regimen, or for any other issue necessitating medical advice.

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