My Mama’s Sweet Potato Casserole recipe is loaded with marshmallows, butter, cinnamon and a secret ingredient to win the title of best Thanksgiving side dishes!

Sweet Potato Casserole with toasted marshmallows and a big spoonful pulled out of it.

There is only one Sweet Potato Casserole recipe that matters and that is my Mama’s homemade sweet potato casserole with marshmallows!

This casserole recipe is very easy to make and can be made a day ahead for an easy Thanksgiving side dish.

We have been making this exact recipe for as long as I can remember and it is by far my favorite version I have ever tried. 

I think it all comes down to that secret ingredient my Mom adds. It comes in a can and is extra creamy. Any guesses what it is?

Sweet Potato Casserole with toasted marshmallows and a big spoonful pulled out of it.

Why, it’s sweetened condensed milk of course!

If you have been around long enough, you know how much my Mom likes to sneak that into sweet recipes. 

Just like in the now famous Mama’s Best Banana Pudding, the sweetened condensed milk adds the perfect sweetness and creaminess to the recipe. 

I have tried making sweet potato casserole many other ways. With milk, cream and even evaporated milk. 

I have also tried regular sugar, brown sugar and maple syrup…but I always come back to using sweetened condensed milk.

Sweet Potato Casserole Ingredients on a wood board: marshmallows, peeled and cubed sweet potatoes, sweetened condensed milk, butter, cinnamon, nutmeg and salt.

Other than our secret ingredient of sweetened condensed milk, the rest of this Sweet Potato Casserole recipe is very standard.

Some people add eggs to their Sweet Potato Casserole and for the life of me I can not figure out why. 

To me, when you add eggs, the final product turns out more like a soufflé. 

That’s just not the way we made it growing up and I prefer the denser texture of perfectly seasoned and mashed sweet potatoes instead. 

Sweet Potato Casserole in 9x13 white casserole dish with toasted marshmallows on top.

To start, we boil our peeled and cubed sweet potatoes in water on the stove until fork tender. 

Then we add melted butter, sweetened condensed milk, cinnamon, nutmeg and salt. Then you mash away and transfer it into a greased 9×13 casserole dish. 

If you want to make this Sweet Potato Casserole ahead of time, this is where you will stop and pop it into the fridge.

Cover the casserole dish with a lid, cling warp or foil. Then keep it refrigerated until you are getting close to being ready to serve it. 

I included these make ahead steps and directions in the recipe below! 

Sweet Potato Casserole on a white plate with a bite being taken out of it.

The final step is to load on those marshmallows all on top of the mashed sweet potatoes. 

I like to use large marshmallows — just look at that glorious marshmallow to sweet potato ratio — but you can use minis if you prefer. 

Then we bake the casserole at 350°F for a few minutes to make sure everything is hot and to let the marshmallows on top get perfectly toasted.

The nice part about this casserole, it can sit on the counter for a while and wait for your other Thanksgiving side dishes to be ready. Then they can all go into the oven together! 

Sweet potato casserole with marshmallows being scooped out of casserole dish. 

If you are looking for perfect Thanksgiving side dishes, I also highly recommend you check out my recipe for The Best Green Bean Casserole — just read all the reviews!

I also have an amazing Cranberry Orange Relish that is requested year after year at our Thanksgiving. This is another great make ahead Thanksgiving side dish that only get’s better with time! 

For dessert, I have so many…but I will recommend these top three Thanksgiving desserts: Pumpkin Dream Cake, Pumpkin Pie Crisp and Caramel Apple Dump Cake

I am so excited to finally be sharing the recipe for my Mama’s famous Sweet Potato Casserole recipe! 

I know Thanksgiving is my favorite eating holiday and the family recipes are what make it so good. 

Sweet Potato Casserole

Yield: serves 10 - 12
Prep Time: 25 minutes
Cook Time: 15 minutes
Total Time: 40 minutes
My Mama's Sweet Potato Casserole recipe is loaded with marshmallows, butter, cinnamon and a secret ingredient to win the title of best Thanksgiving side dishes!

Ingredients

  • 2.5 lbs sweet potatoes, peeled and diced
  • 8 tablespoons (1 stick) butter, melted
  • 1 (14 oz) can sweetened condensed milk
  • 1 tablespoon cinnamon
  • 1/2 teaspoon nutmeg
  • 1/2 teaspoon salt
  • 1 (16 oz) bag large marshmallows

Instructions

  1. Preheat oven to 350°F. Spray a 9x13 casserole dish with non stick spray and set aside. 
  2. In a large stock pot, add sweet potatoes and cover with water. Cover pot with lid, bring to a boil and cook until fork tender, about 15 minutes. 
  3. Drain potatoes and transfer back to pot. Add butter, sweetened condensed milk, cinnamon, nutmeg and salt. 
  4. Mash away until nice and smooth. Pour potato mixture into prepared baking dish and smooth out the top.  
  5. Line the top of the casserole with marshmallows and bake until marshmallows are lightly toasted, about 15 to 20 minutes.

Notes

Make Ahead Note: If you make this ahead, do not add marshmallows ahead of time. Instead, store sweet potatoes in the fridge covered with foil. Heat them in oven for 15 minutes (still covered with foil), then remove from oven and continue on with step #5. 

Recommended Products

I am an Amazon affiliate member and I earn a small percentage from qualifying purchases. Thank you!

My Mama's Sweet Potato Casserole recipe is loaded with marshmallows, butter, cinnamon and a secret ingredient to win the title of best Thanksgiving side dishes! #SweetPotatoCasserole #Thanksgiving #ThanksgivingSideDish #ThanksgivingCasserole #Casserole