Sweet Potatoes au Gratin

Sweet Potatoes au Gratin is the dish you need to add to your Thanksgiving spread. Sweet potatoes baked in heavy cream with cinnamon, nutmeg, and parmesan. 

Think of this delicious Side Dish as the perfect combinations of Potatoes au Gratin and Candied Yams. It has the sweetness from the yams with classic holiday spices, plus it’s all baked in a cheesy cream. 

Sweet Potatoes Au Gratin serving on spatula


“Au Gratin” is a French term that refers to something that is cooked with a browned topping. Usually, it’s made with a topping of bread crumbs or, as in this case, cheese. It perfectly describes these sweet potatoes that are smothered in a creamy parmesan mixture and cooked to perfection.

You may have heard the term before for Brussel Sprout Gratin, another easy side dish perfect for the holidays. Just like with these sweet potatoes, the crisp and tender Brussel Sprouts are covered in melty parmesan cheese that just melts in your mouth. 

This recipe is a sweet variation on classic Potatoes Au Gratin. Using yams instead of typical potatoes makes this dish a surprising and wonderful combination of sweet and savory. Heavy cream, egg, salt, cinnamon, nutmeg, black pepper and Parmesan cheese are all whisked together in a custard that you pour over the sweet potatoes. While in the oven, the sweet potatoes become tender and absorb the rich flavors around them. 

Serve your cheesy sweet potatoes with your Thanksgiving or Christmas dinner for a side dish that’s sure to be a favorite. This recipe is also easy enough you don’t have to save it for a big holiday dinner. Sweet Potatoes au Gratin are ready for the oven in just 10 minutes. Toss them together and cook yourself some wonderfully cheesy sweet potatoes for a regular weeknight dinner.



  • Prep: Preheat your oven to 375 degrees and spray your baking dish with a non-stick spray, so they’re both ready once the potatoes are. 
  • Sweet Potatoes: Peel 2 large sweet potatoes and slice them to about 1/4 inch thick circles. Add them in layers to your prepared baking dish. 
  • Custard: Add heavy cream, egg, salt, cinnamon, nutmeg, black pepper and Parmesan cheese to a large bowl. Whisk all the ingredients together until smooth. Pour the custard evenly over the sweet potatoes. 
  • Bake: Cook your Sweet Potatoes au Gratin uncovered for 45-50 minutes.

Sweet Potatoes Au Gratin in baking dish


  • Cheese: You can make this recipe even cheesier by adding in some shredded cheddar or Gruyere. Prepare the custard as usual and pour it over the sweet potatoes. Then sprinkle the extra cheese over the top of the Sweet Potatoes Au Gratin. 
  • Breadcrumbs: Au Gratin classically refers to a cheese or breadcrumb topping. To make a breadcrumb topping for your sweet potatoes mix some Panko breadcrumbs with melted butter and parmesan cheese. Sprinkle the mixture over the top before baking. 
  • Bacon: To take your Gratin to the next level add in some bacon bits. You can mix the cooked bacon pieces in with the custard, then pour it over the sweet potatoes and bake. 



  • Serve: Once you’ve baked Potatoes au Gratin, they’re best fresh from the oven. Don’t leave them out at room temperature for more than 2 hours. 
  • Store: Let the potatoes cool to room temperature before storing them. Cover the baking dish in tin foil or plastic wrap, or move the Potatoes Gratin to an airtight container. They’ll keep well in the fridge for 3-5 days. 
  • Freeze: Properly sealed in an airtight container, your potatoes will keep well in the freezer for up to 3 months. 

Sweet Potatoes Au Gratin serving on plate

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Sweet Potatoes au Gratin

Sweet Potatoes au Gratin is the dish you need to add to your Thanksgiving spread. Sweet potatoes baked in heavy cream with cinnamon, nutmeg, and parmesan.
Course Side Dish
Cuisine American
Keyword Sweet Potatoes au Gratin
Prep Time 10 minutes
Cook Time 45 minutes
Total Time 55 minutes
Servings 8 Servings
Calories 300 kcal
Author Sabrina Snyder


  • 2 cups heavy cream
  • 1 large egg
  • 1 teaspoon kosher salt
  • 1/4 teaspoon cinnamon
  • 1/4 teaspoon ground nutmeg
  • 1/8 teaspoon coarse ground black pepper
  • 1/4 cup Parmesan cheese , grated
  • 2 large sweet potatoes , peeled and sliced 1/4 inch thick


  1. Preheat oven to 375 degrees and spray an 8x8 baking dish with vegetable oil spray.
  2. In a large bowl whisk together the heavy cream, egg, salt, cinnamon, nutmeg, black pepper and Parmesan cheese until smooth.
  3. Add sweet potatoes to your baking dish and carefully pour the custard over the sweet potatoes.
  4. Bake, uncovered, for 45-50 minutes.

Nutrition Facts
Sweet Potatoes au Gratin
Amount Per Serving
Calories 300 Calories from Fat 207
% Daily Value*
Fat 23g35%
Saturated Fat 14g88%
Cholesterol 107mg36%
Sodium 419mg18%
Potassium 340mg10%
Carbohydrates 19g6%
Fiber 3g13%
Sugar 4g4%
Protein 4g8%
Vitamin A 12992IU260%
Vitamin C 2mg2%
Calcium 105mg11%
Iron 1mg6%
* Percent Daily Values are based on a 2000 calorie diet.

About the Author: Sabrina Snyder

Sabrina is a professionally trained Private Chef of over 10 years with ServSafe Manager certification in food safety. She creates all the recipes here on Dinner, then Dessert, fueled in no small part by her love for bacon.

Dinner, then Dessert, Inc. owns the copyright on all images and text and does not allow for its original recipes and pictures to be reproduced anywhere other than at this site unless authorization is given. If you enjoyed the recipe and would like to publish it on your own site, please re-write it in your own words, and link back to my site and recipe page. Read my disclosure and copyright policy. This post may contain affiliate links.


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