September 15, 2021| By

Sweet Potato Marshmallow Bars

Prep Time: 30 minutes
Cook Time: 40 minutes
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These homemade Sweet Potato Marshmallow Bars are so fluffy and buttery! They're perfect treat for when you want something sweet! Three words to describe these bars? Decadent, sweet, and indulgent!

If you love this recipe, you must try this Sweet Potato Pie, Sage Browned Butter Pumpkin Pie and these decadent Homemade Snickers Bars!

Sweet Potato Marshmallow Bars on a piece of parchment paper

These Sweet Potato Marshmallow Bars are one of those recipes where you take your first bite and automatically - your eyes roll to the back of your head and your tastebuds immediately say "omg". The bars are soft and airy. They're also super flavorful and moist due to the combination of sweet potato puree and my homemade pumpkin spice recipe.

Also, the toasted marshmallow topping is homemade. While you can use store bought marshmallow fluff, I highly recommend trying this recipe to make your own. It's a bit messy but so worth it when you sink your teeth in to take a bite. Sheer perfection.

side angle photo of sweet potato marshmallow bars

how do you make sweet potato marshmallow bars?

The bars themselves are pretty simple to make. It's a one bowl recipe where you literally combine all of the ingredients together and mix until the batter is smooth.

1. make the sweet potato bars

  • Combine room temperature butter and both brown and white sugar and mix together until nice and smooth. *It's important to mix these two together before adding in the remainder of the ingredients because this is what makes the bars light and fluffy!
  • Then add in the eggs, sweet potato puree, vanilla extract, and pumpkin spice.
  • Lastly, add in the kosher salt, baking powder, baking soda, and flour into the mix and mix until smooth.

2. then make the marshmallow fluff topping

  • While blondies are baking, get started on making the marshmallow fluff. Bring about 1 inch of water to a boil in a sauce pan. Then in a large bowl, combine egg whites and sugar. Set bowl on top of the boiling water (to create a double boiler) and constantly mix together until sugar is dissolved, about 5 minutes. Mixture should be thick and globby.
  • Add egg white mixture to the bowl of a stand mixer with the whisk attachment and mix on high until a fluff forms - it should be glossy and white. Add cream of tartar and vanilla extract and continue to whisk until stiff peaks form. This will take about 8-10 minutes.
a front photo of the recipe

tips and tricks

  • Just as a heads up, I used canned sweet potato puree for this recipe. So, don't worry about making your own sweet potato puree. Save yourself a good hour of time and use the canned stuff - it's just as good!
  • When making the batter, be sure to scrape down the sides of the bowl when needed to ensure that all ingredients are fully mixed together!
  • You can use store bought marshmallow if you don't want to make your own! I recommend Kraft jet puffed marshmallow creme!
  • When making the marshmallow fluff, be sure not to bring the egg whites and sugar mixture to a boil when heating over the sauce pan. Also, be sure to mix constantly so that the egg whites do not cook.
  • Also, for the marshmallow fluff, be sure to be patient when whisking it together in the stand mixer. It can take about 8-10 minutes to form stiff peaks, so don't get discouraged!
overhead photo of recipe

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Sweet Potato Marshmallow slices cut on a piece of parchment paper

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Let's stay connected on social media and continue to cook together! Also, if you decide to make this recipe, please leave a star rating on the recipe card and leave a comment below! Tag @BritneyBreaksBread on Instagram and hashtag #britneybreaksbread so I can see your creations! I hope that you love this recipe as much as we do!

overhead photo of recipe

Sweet Potato Marshmallow Bars

These homemade Sweet Potato Marshmallow Bars are so fluffy and buttery and the perfect treat for when you want something sweet! Perfectly spiced, rich, and indulgent.
Serving: 9 servings
Prep Time: 30 minutes
Cook Time: 40 minutes
Calories: 300kcal

Ingredients

Sweet Potato Blondies

  • 2 sticks salted butter (1 cup / 227g), room temperature
  • 1 cup brown sugar
  • ½ cup sugar
  • 2 eggs, room temperature
  • ½ cup sweet potato puree
  • 1 tbsp vanilla extract
  • ½ tsp kosher salt
  • 1 tsp baking powder
  • ½ tsp baking soda
  • 2 cups all-purpose flour

Marshmallow Fluff

  • 1 cup egg whites
  • 2 cups sugar
  • pinch of salt
  • 1 tsp vanilla extract
  • 2 tsps cream of tartar

Directions

  • Preheat oven to 350 degrees F. With the paddle attachment, combine room temperature butter, brown sugar, and sugar in a stand mixer. (you can also use a hand mixer if you do not have a stand mixer) Beat together on medium until sugar and butter are fully incorporated, about 30 seconds to 1 minute. Scrape down the sides of the bowl as needed.
  • Add eggs, one at a time, then sweet potato puree, vanilla extract, and . (Mixture may look gritty, however, keep going. Once the flour is added, the batter will become smooth)
  • Add salt, baking powder, baking soda, and flour. Continue to mix until all dry ingredients are fully incorporated. Scrape down the sides of the bowl and continue to mix for another 10-15 seconds.
  • Spray an 8x8 baking pan with nonstick baking spray OR line with parchment paper. Add batter and spread evenly throughout pan. Sprinkle top of batter with brown sugar. Bake for 40 minutes.
  • (if using store bought marshmallow fluff, skip steps 5u00266) While blondies are baking, make the marshmallow fluff. Bring about 1 inch of water to a boil in a sauce pan. In a large bowl, combine egg whites and sugar. Set bowl on top of boiling water and constantly mix together until sugar is dissolved, about 5 minutes. Mixture should be thick and globby.
  • Add egg white mixture to the bowl of a stand mixer with the whisk attachment and mix on high until a fluff forms - it should be glossy and white. Add cream of tartar and vanilla extract and continue to whisk until stiff peaks form. This will take about 8-10 minutes.
  • Once blondies are finished, let them cool completely on a cooling rack. Once blondies they have cooled, lather on the marshmallow fluff. Create swirls and char with a torch!

Nutrition

Calories: 300kcal
Course: Dessert
Cuisine: American

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  1. 4 stars
    They were a huge hit with my family to the point where I asked if my dad tried one and my mom said “No, [your sister] got mad at your father and hid them as punishment.” Ever since he was young, my dad has been obsessed with fluff so this was kind of cruel, and probably led to him fake crying.

    How it went: The cake went smoothly. It is definitely a denser spiced cake. I made the marshmallow using a cup of liquid egg white from the carton. I’m guessing Britney used regular egg whites because I ended up having to use an extra half a teaspoon of cream of tarter to get it to stiffen. If you use regular egg whites you could probably get things a bit fluffier than I did. I didn’t have a blow torch, so I finished off the marshmallow topping by putting the whole cake under the broiler and rotating to brown the marshmallow. It didn’t come out as pretty as Britney’s, but was still delicious. They are very sweet! But what else would you expect with a marshmallow dessert? A wonderful Fall treat! Only deducted a star because figuring out how to get the marshmallow topping right was a bit of work, however, if you use regular egg whites you may have an easier time.

    • Thanks so much for giving this recipe a try! I'm so glad that you enjoyed it even with the modifications!

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