Sweet Potato Bars with Swirled Marshmallow Topping
what to expect:
Prep Time: 1 hour 15 minutes | Cook Time: 45 minutes | Total Time: 2 hours
(includes time to roast sweet potatoes)
Yield: 9 Bars
Warm and cozy cake-like bars made with roasted orange sweet potato and flavored with cinnamon and nutmeg. Store-bought marshmallow spread gives these bars a beautifully swirled toasted marshmallow topping.
*For helpful tips and how-to’s, be sure to read the whole post!
These sweet potato bars are moist, sweetened with roasted orange sweet potatoes and brown sugar, cozy with fall spices, and have the signature feel of biting into a toasted marshmallow thanks to marshmallow spread swirled into the top of the batter.
To be totally honest, I don’t like sweet potatoes and even I like these bars. If you enjoyed my white chocolate chip pumpkin bars, these are going to be right up your alley.
If you’re looking for another well-loved sweet potato recipe (maybe you roasted too many sweet potatoes – been there), check out my recipe for Fluffy and Soft Sweet Potato Pancakes.
What You’ll Find in This Post
- What You’ll Need (Ingredients & Tools)
- Helpful Tip: Roasted Sweet Potatoes are a Must
- Helpful Tip: Getting a Perfectly Swirled Topping
- Helpful Tip: Knowing When They’re Done
What You’ll Need to Make Sweet Potato Bars with Swirled Marshmallow Topping
Ingredients for Sweet Potato Bars
- Unsalted Butter – melted
- All-Purpose Flour
- Baking Powder
- Kosher Salt
- Ground Cinnamon
- Ground Nutmeg
- Orange Sweet Potato – roasted and mashed
- Brown Sugar
- Large Egg
- Marshmallow Spread (such as Jet Puff Marshmallow Creme or Marshmallow Fluff)
Tools & Equipment for Sweet Potato Bars
You probably already have everything you’ll need to make these sweet potato bars.
You’ll need two medium mixing bowls, a whisk, a spatula, a spoon, and an 8-inch x 8-inch baking dish (I used a glass baking dish).
How to Roast Sweet Potatoes for Sweet Potato Bars
To get the most flavor out of your sweet potatoes, you’ll want to roast them. Luckily, that’s as simple as piercing the skins with a fork and throwing them in the oven for 45 minutes to an hour.
You’ll know they’re done when you can pierce a kitchen knife through the thickest part of the sweet potato with no resistance.
Once they’re cool, peel the skins off and mash with a fork.
Roasting and mashing the sweet potatoes can be done ahead of time to save time when making the batter.
How to Get a Perfectly Swirled Marshmallow Topping
It took several thorough tests to land on the ideal method to get a beautifully swirled marshmallow topping for your sweet potato bars.
Once you’ve made your sweet potato bar batter, you’ll set aside a quarter cup of the batter so that you can spoon it on top of the marshmallow spread.
After adding the marshmallow spread to the baking dish, you’re going to spoon six dollops of the batter evenly over the top of the baking dish and then swirl it into the marshmallow with the back of a spoon.
How to Know When Your Sweet Potato Bars are Done
Because you can’t see the batter as these sweet potato bars bake, it can be difficult to know when they’re done baking.
My tried and true test is giving the pan a gentle shake. If the very middle doesn’t jiggle at all, the sweet potato bars are done.
Everyone’s oven is different, so I recommend checking on them at the 40-minute mark and giving them a shake. You’ll also want to keep an eye on the marshmallow topping to make sure it doesn’t burn. We’re looking for perfectly golden brown.
If your marshmallow topping is getting to be too brown, but the bars still need more time to bake, you can tent the pan with some aluminum foil. This keeps the top from burning while still giving it time to bake.
If you make these sweet potato bars with marshmallow fluff, let me know how they turned out by leaving a review! And if you post on Instagram, be sure to tag me @ficklebea. I can’t wait to see what you make – happy baking!
If you are new to baking or nervous about spending time in the kitchen, check out My Kitchen Commandments for some helpful tips!
PrintSweet Potato Bars with Swirled Marshmallow Topping
Warm and cozy cake-like bars made with roasted orange sweet potato and flavored with cinnamon and nutmeg. Store-bought marshmallow spread gives these bars a beautifully swirled toasted marshmallow topping.
- Prep Time: 1 hour 15 minutes
- Cook Time: 45 minutes
- Total Time: 2 hours
- Yield: 9 bars 1x
- Category: Dessert
- Method: Baking
- Cuisine: American
Ingredients
8 Tablespoons Unsalted Butter ( 110 grams) – melted
1 1/4 cup All-Purpose Flour (170 grams) *
1/2 teaspoon Baking Powder (2 grams)
1/4 teaspoon Kosher Salt (0.5 grams)
3/4 teaspoon Ground Cinnamon (3 grams)
1/4 teaspoon Ground Nutmeg (0.5 grams)
1 cup Mashed Orange Sweet Potato (275 grams), about 1 small sweet potato – roasted and mashed in advance
3/4 cup Brown Sugar (192 grams) – packed
1 Large Egg (50 grams)
7 oz. Marshmallow Spread (such as Jett Puffed Marshmallow Creme or Marshmallow Fluff)
Instructions
Roast the Sweet Potato
- Preheat oven to 425 Fahrenheit (218 Celsius) and line a baking tray with aluminum foil for easy clean-up.
- Wash and dry the whole sweet potato(es) and then pierce the skins all over with a fork.
- Place the pierced sweet potatoes on the lined baking sheet and bake for 45-60 minutes or until tender.
You should be able to pierce a sharp kitchen knife through the thickest part of the potato with no resistance. - Let the potato(es) cool, then peel and mash with a fork.
- Place mashed potatoes in a covered container in the fridge if making ahead.
Make the Sweet Potato Bar Batter
- Preheat your oven to 350 Fahrenheit (177 Celsius) & grease an 8-inch x 8-inch glass baking dish.
- If you haven’t done so already, melt your butter by cutting it into Tablespoon-sized slices and microwaving for 20-second increments, gently swirling in between, until melted.
- In a medium-sized bowl, whisk together the all-purpose flour, baking powder, kosher salt, ground cinnamon, and ground nutmeg.
- In a separate medium-sized bowl, whisk together the mashed orange sweet potato, brown sugar, and egg. It’s okay if you still have some sweet potato chunks after whisking.
- Add half of the melted butter to the sweet potato mixture and whisk until there are no butter streaks. Repeat with the second half of the melted butter.
- Pour the wet ingredients into the dry ingredients, scraping the bowl of the wet ingredients to make sure none of the mixture is left behind.
- Whisk the wet and dry ingredients together until you get a smooth batter with no flour patches.
- Set aside 1/4 cup of the batter and then pour the remainder into the greased baking dish.
Top & Bake the Sweet Potato Bars
- Using a spatula, top the batter in the baking dish with the marshmallow spread, gently smoothing it until it covers the entire top of the batter.
- Using a spoon, place five to six dollops of the reserved batter on top of the marshmallow spread, scattered over the top evenly.
- Using the back of the spoon, gently swirl the dollops into the marshmallow spread until you have a swirled pattern.
- Bake for 45-50 minutes, or until the middle no longer jiggles and the marshmallows are golden brown. If you notice the marshmallows are getting too brown, you can tent the baking dish with aluminum foil.
- Best served warm while the top is a little crispy.
Notes
* Scooping your flour directly from the bag will result in sweet potato bars that are much denser and drier than intended. To make sure you’re getting a result closest to the intended result, measure your flour by doing the following:
- Give the flour in the bag a gentle stir with a spoon to break up any dense spots.
- Gently spoon the flour into your measuring cup, making sure not to shake the measuring cup to level out the flour in the cup.
- Using the flat side of a knife or the handle of your spoon, level off the top of the measuring cup then use it in the recipe.
To help with your grocery shopping, I’ve provided the ingredients for this recipe below and organized them by where they’re generally located in the store:
Produce:
- Whole Orange Sweet Potato
Dairy:
- Unsalted Butter
- Large Egg
Pantry:
- All-Purpose Flour
- Baking Powder
- Kosher Salt
- Ground Cinnamon
- Ground Nutmeg
- Brown Sugar
- Marshmallow Spread (typically found in the baking aisle near to the marshmallows)
Nathan says
I substituted gluten-free flour in this recipe and made several mistakes along the way – still turned out delicious!
Sierra says
Thanks Nathan – happy to hear it! 🙂