Healthy Sweet Potato Casserole

Melissa

By: Melissa

Updated: October 15, 2025

Don't be fooled! This sweet potato casserole might be topped with marshmallows, but it's actually a healthy version of the Thanksgiving classic. This easy dairy free side dish is made with just a hint of brown sugar, and can easily be made vegan or gluten free with a simple swap.

Sweet potato casserole in a cast iron skillet.

What makes this sweet potato casserole healthy?

Traditional sweet potato casserole starts with butter, milk and a decent amount of brown sugar. Obviously, not diet or dairy free friendly.

Personally, I think that sweet potatoes are already sweet enough, and I often add a nice pinch of salt when making mashed sweet potatoes because I think it brings the sweet potatoes and cinnamon to life.

To make the healthy, while still making it indulgent, I kept the marshmallows and pecans on top and I added just enough brown sugar to give you a taste. I think it’s a perfect match for savory Thanksgiving turkey and its creamy side dishes.

Searching for more Thanksgiving recipes? homemade stuffing recipe / easy drop biscuits / pancetta chestnut stuffing / easy cranberry bars / spiced cranberry sauce

Sweet potato casserole in a cast iron skillet, with a spoon removing a scoop.
Sweet potato casserole in a cast iron skillet, with a spoon removing a scoop, focused on the spoon.

Ingredient notes:

  • Marshmallows – To make this gluten free, use a friendly version of marshmallows (or leave them off). To make this vegan, swap the marshmallows for your favorite plant based marshmallows.
  • Egg – For a vegan option, substitute a flax egg by mixing 1 tablespoon of ground flaxseed with 2 tablespoons of water in place of the egg.

Making changes to a recipe can result in recipe failure. Any substitutions listed below are simple changes that I believe will work in this recipe, but results are not guaranteed.

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Melissa’s tips + tricks:

  1. Keep the water level low. You really don’t to cover your sweet potatoes with water to steam them. Halfway up will do. They’ll cook much quicker with less water. When they’re fork tender, drain them (I just use the lid to keep them in the pot, but you can use a colander if you want).
  2. Don’t end up with scrambled eggs: Beat your egg in a small bowl or measuring cup until it’s smooth. Then pour it into the sweet potatoes while you beating them. This helps prevent you from getting scrambled eggs
  3. Need to prepare this sweet potato casserole ahead of time? You can easily make this dish ahead of time. I recommend getting it in the baking dish with toppings, and storing it in the refrigerator until you’re ready to bake it. Remove it from the fridge for about an hour before you bake.
Sweet potato casserole in a cast iron skillet, with a scoop removed.
Sweet potato casserole in a cast iron skillet.
Sweet potato casserole in a cast iron skillet.

Healthy Sweet Potato Casserole

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Prep Time 20 minutes
Cook Time 30 minutes
Total Time 50 minutes
Servings 8 servings
Don't be fooled! This sweet potato casserole might be topped with marshmallows, but it's actually a healthy version of the Thanksgiving classic. This easy dairy free side dish is made with just a hint of brown sugar, and can easily be made vegan or gluten free with a simple swap.

Ingredients

  • 3 large sweet potatoes - peeled and cubed
  • 1 tablespoon brown sugar
  • 1/4 – 1/2 teaspoon cinnamon
  • Pinch of coarse salt
  • 1 egg
  • 1/3 cup toasted pecan pieces
  • 1/3 cup mini marshmallows
  • Cinnamon and brown sugar for sprinkling

Instructions

  • Mise en place. Preheat oven to 400˚F. Peel and cube your sweet potatoes and measure the rest of the ingredients before starting.
  • Steam your sweet potatoes. Preheat oven to 400˚F. Place cubed sweet potatoes in a large saucepan and fill halfway with water. Cover pot and bring water to a boil. Cook until sweet potatoes are fork tender, about 10 minutes. Drain potatoes and return to pot. Add brown sugar, cinnamon and salt.
  • Mash the potatoes. In a small bowl or cup, beat the egg thoroughly to make them easier to incorporate into the casserole.
    Then, use an electric mixer to mash the sweet potatoes until smooth. While continuing to beat the sweet potatoes, slowly pour in the egg. Continue to beat for 1 minute, or until the sweet potato mixture is light and fluffy.
  • Bake the casserole. Transfer to a baking dish and lightly sprinkle with brown sugar and cinnamon. Top with pecan pieces and marshmallows. Bake for 10 – 15 minutes or until marshmallows are toasted and eggs have fully set. Remove from oven and allow casserole to cool for about 10 minutes before serving.

Nutrition

Calories: 125kcal Carbohydrates: 21g Protein: 2g Fat: 4g Trans Fat: 0.003g Cholesterol: 20mg Sodium: 57mg Fiber: 3g Sugar: 6g Vitamin C: 2mg