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Sweet Potato Casserole with Marshmallows and Pecan Streusel

  • Serves: 10
  • Prep Time: 25 min
  • Cook Time: 45 min
  • Calories: 368
baked Homemade Sweet Potato Casserole with Marshmallows and Pecan Streusel in a baking dish being scooped with a wooden spoon

It’s not Thanksgiving dinner until there’s a sticky, rich, delicious pecan-and-marshallow topped sweet potato casserole baking in the oven. And our sweet potato casserole recipe is the best ever!

A Super Classic All-American Sweet Potato Casserole That’s Sweet as Can Be

Grandma knew a thing or two about what people really want on the table on Thanksgiving, and as much as we love recipes that bring a little freshness to the table, we’ve got a super soft spot in our junk-food loving hearts for classic, sticky, creamy, rich sweet potato casserole. And why is our sweet potato casserole recipe the best ever? Well, we pull NO punches and we haven’t modernized it in the slightest! We’ve got good old mini-marshmallows—layers of them—along with a fluffy, sweet, creamy sweet potato filing and a toasty, sweet pecan streusel topping that takes things way over the top in this is-it-a-dessert-or-is-it-a-side-dish recipe.

ingredients for sweet potato casserole with marshmallows and pecan streusel in bowls on a counter

Sweet Potato Casserole Ingredients—Starting With Those Mini-Marshmallows!

We’re betting that the grocery list for this sweet potato casserole recipe is going to overlap a lot with all of the other ingredient lists you’ve got going for Thanksgiving. Warm, holiday baking spices, heavy cream, butter, pecans. You probably need those same things for making pies, mashed potatoes and, well, everything else that’s going on that heavily-laden holiday table! You can buy all of it way ahead of time, too, if you’re a super prepared person. Here’s everything you’ll need to make this classic, easy sweet potato casserole:

  • Sweet potatoes

  • Brown sugar

  • Maple syrup

  • Vanilla

  • Lemon

  • Heavy cream

  • Eggs

  • Cinnamon, ginger, nutmeg

  • Pecans

  • Mini marshmallows

  • Butter

  • Flour

melted butter, pecans, salt, brown sugar, flour and cinnamon in a mixing bowl on the counter
sweet potato casserole pecan streusel topping in a mixing bowl on the counter

Why Do Americans Put Marshmallows on Sweet Potato Casserole? A Brief History of Sweet Potato Casserole With Marshmallow Topping.

This is a fantastic question, because—even though many of us grew up eating sweet potato casserole with marshmallows on it—this is kind of an oddball recipe when you stop and think about it. Like a lot of oddball recipes, this one actually grew out of a marketing scheme! What else? Back in the early 1900s, a company called Angelus Marshmallows was trying to get Americans to eat more of their fluffy, squishy marshmallows and so they came up with a bunch of recipes that featured marshmallows, one of which was the now-classic, marshmallow-topped sweet potato casserole. You can read more about the history of this very American dish over on the Smithsonian’s website.

cubed cooked sweet potatoes in a large pot
mashed sweet potatoes in a large pot
mashed sweet potatoes, butter, brown sugar, maple syrup, vanilla, lemon juice, heavy cream, eggs and spices  in a large pot
uncooked sweet potato casserole in a baking dish

How To Make Sweet Potato Casserole with Marshmallows

Our sweet potato casserole recipe is designed to be easy, of course, but also to be the best sweet potato casserole recipe ever. So it’s easy, but it’s not open-a-few-cans easy. Because best is more important than easy on a day like Thanksgiving, right? So here’s how to make this traditional sweet potato casserole:

  1. Cook the sweet potatoes!

  2. Mix together the butter , salt, brown sugar, flour and cinnamon to make the streusel topping.

  3. Smash together the potatoes, butter, brown sugar, maple syrup, vanilla, lemon juice, heavy cream, salt, eggs, nutmeg, cinnamon and ginger to make the filling!

  4. Spread the sweet potato mixture in a baking dish.

  5. Top it with marshmallows, streusel, pecans and more mini-marshmallows.

  6. Bake! It’ll take about 30 minutes.

unbaked sweet potato casserole topped with marshmallows
unbaked sweet potato casserole topped with marshmallows and pecan streusel topping

Thanksgiving Game Plan: Make Your Sweet Potato Casserole Ahead of Time!

One of the best things about sweet potato casserole is that you can make it ahead of time! Simply make it all the way through to the point of baking, and stop right before you’d put it in the oven. Then, cover your sweet potato casserole with foil and store it in the refrigerator for up to 24 hours. When you’re ready to bake it, pull it out of the oven and let it come to room temperature. Then pop it in a preheated oven and bake! Yay for anything you can do ahead of time on the oven-and-stove juggle that is Thanksgiving Day! Unfortunately, this sweet potato casserole doesn’t freeze well.

baked Homemade Sweet Potato Casserole with Marshmallows and Pecan Streusel in a baking dish
baked Homemade Sweet Potato Casserole with Marshmallows and Pecan Streusel in a baking dish

More Sweet Potato Recipes for your Thanksgiving Table

Tools You’ll Need

baked Homemade Sweet Potato Casserole with Marshmallows and Pecan Streusel in a baking dish
baked Homemade Sweet Potato Casserole with Marshmallows and Pecan Streusel in a baking dish being scooped with a wooden spoon

Happy Holidays!

It’s the most wonderful time of year to get into the kitchen with your loved ones and get cooking! We hope this sweet potato casserole recipe is exactly what you’re looking for. When you try it, we’d love to hear about it! Share a photo and tag us on Instagram using @themodernproper and #themodernproper so that we can see your stuff! Happy eating!

Sweet Potato Casserole with Marshmallows and Pecan Streusel

  • Serves: 10
  • Prep Time: 25 min
  • Cook Time: 45 min
  • Calories: 368

Ingredients

  • 3 tsp Sea salt
  • 3 lbs Sweet potatoes (about 3-4 large sweet potatoes), peeled and cut into 2-inch pieces
  • 1/4 cup Unsalted butter, melted, 4 tbsp
  • 1/4 cup Brown sugar, packed
  • 2 Tbsp Maple syrup
  • 1 tsp Vanilla extract
  • 1 Tbsp Lemon juice
  • ¼ cup Heavy cream
  • 2 Eggs
  • 1/8 tsp Nutmeg
  • 1/2 tsp Cinnamon
  • 1/4 tsp Ground ginger
  • 1/3 cup Chopped pecans
  • 2 cups Mini marshmallows

Streusel Topping

  • 1/4 cup Unsalted butter, melted, 4 tbsp
  • 1/4 tsp Sea salt, (skip if using salted butter)
  • 1/3 cup Brown sugar, packed
  • 1/3 cup Flour
  • 1/2 tsp Cinnamon

Method

  1. Preheat oven to 350°F. Grease a 9x13 inch baking dish.

  2. Boil the sweet potatoes: Bring a large pot of water along with 2 teaspoons salt to a boil over high heat. Add the sweet potatoes and simmer until fork-tender, about 15 minutes.

  3. Make the streusel topping: Mix the ¼ cup melted butter, ¼ teaspoon salt, ⅓ cup brown sugar, flour and cinnamon together in a small bowl until combined. Press it together into a few large pieces. Store in the fridge until you're ready to use it.

  4. Drain the sweet potatoes and return them to the pot. Using a potato ricer or masher, mash the cooked sweet potatoes together with the remaining ¼ cup butter, ¼ cup brown sugar, maple syrup, vanilla, lemon juice, heavy cream, remaining 1 teaspoon salt, eggs, nutmeg, cinnamon and ginger, until smooth.

  5. Spread the sweet potato mixture evenly in the baking dish. Top it with 1 1/2 cups of marshmallows, followed by the streusel topping, crumbling it into pieces.

  6. Sprinkle the casserole with the pecans followed by the remaining 1/2 cup marshmallows.

  7. Bake for 25-30 minutes, until the marshmallow topping has browned. If the marshmallows start to brown too quickly, spray some foil with cooking spray and cover the dish, oil side down, taking care to not let it come in contact with the top of the casserole. Let sit for 5 minutes before serving.

*To make this casserole a day ahead of time, stop after step 6 and cover it with foil. Store it in the fridge for up to 24 hours. When you’re ready to bake it, bring the casserole to room temperature, then proceed with step #7.

Nutrition Info

  • Per Serving
  • Amount
  • Calories 368
  • Protein 4 g
  • Carbohydrates 61 g
  • Total Fat 12 g
  • Dietary Fiber 5 g
  • Cholesterol 61 mg
  • sodium 860 mg
  • Total Sugars 18 g

Sweet Potato Casserole with Marshmallows and Pecan Streusel

Questions & Reviews

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  • Myra jones

    To serve Sunday at 1pm, could I make this on Friday NIGHT and refrigerate until Sunday? (more than the recommended 24 hrs?)

    Sure! I would keep the pecan streusel separate until you are ready to bake it.

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