Marshmallow Air Fryer Sweet Potato Casserole

I used to dread making sweet potato casserole every Thanksgiving because it meant heating up my whole kitchen with the oven running for hours. Plus, I could never get the timing right with everything else I was cooking.

Then I discovered you can make this holiday favorite in the air fryer. It cooks faster, doesn’t heat up your house, and honestly tastes just as good as the traditional version. The best part? You free up precious oven space for your turkey and other dishes.

What Kind of Sweet Potatoes Should I Use?

For this casserole, you’ll want to pick up orange-fleshed sweet potatoes, which are the most common variety you’ll find at the grocery store. These have that classic sweet, creamy texture that works perfectly for casseroles. You can use either the longer, tapered sweet potatoes or the shorter, rounder ones – both will give you great results. When selecting your sweet potatoes, look for ones that feel firm and heavy for their size, without any soft spots or wrinkled skin. Since you’ll be cooking them first before making the casserole, don’t worry too much about getting them all exactly the same size, just aim for large ones as the recipe calls for.

Options for Substitutions

This sweet potato casserole is pretty forgiving when it comes to swaps and substitutions:

• Sweet potatoes: You can use canned sweet potatoes (about 3 cups mashed) instead of fresh ones. Just drain them well and skip the cooking step. Butternut squash also works as a substitute, though it’ll give you a slightly different flavor.
• Brown sugar: If you’re out of brown sugar, mix ½ cup granulated sugar with 2 tablespoons molasses, or just use all granulated sugar for a lighter sweetness.
• Pecans: Walnuts, chopped almonds, or even crushed graham crackers make good substitutes. You can also skip the nuts entirely if you have allergies.
• All-purpose flour: For a gluten-free version, use almond flour or oat flour instead. You might need slightly less since these flours can be denser.
• Butter: Coconut oil (solid, not melted) works well in place of the cold butter for the topping. For the melted butter in the filling, you can use melted coconut oil or vegetable oil.
• Mini marshmallows: Regular marshmallows cut into pieces work just fine, or you can skip them altogether for a less sweet version. Some people like adding a streusel topping instead.

Watch Out for These Mistakes While Cooking

The biggest mistake when making air fryer sweet potato casserole is not cooking your sweet potatoes long enough beforehand – they need to be completely tender and mashable, or you’ll end up with lumpy, undercooked chunks in your final dish.

Another common error is adding the topping too early in the cooking process, which can cause your pecans to burn and marshmallows to turn black before the casserole is heated through – wait until the last 5-10 minutes to add these delicate toppings.

Make sure your sweet potato mixture is completely smooth before transferring to the air fryer basket, and don’t forget to check that your air fryer basket isn’t overcrowded, as this can lead to uneven cooking and soggy spots.

For best results, let the casserole rest for a few minutes after cooking so the flavors can settle and it’s easier to serve without falling apart.

What to Serve With Sweet Potato Casserole?

Sweet potato casserole is a natural fit for your Thanksgiving table, but it pairs beautifully with so many other meals too! I love serving it alongside roasted turkey, glazed ham, or even simple grilled chicken for a cozy weeknight dinner. The sweet and nutty flavors work really well with savory green bean casserole, stuffing, and cranberry sauce if you’re going full holiday mode. For a lighter approach, try it with a crisp fall salad with apples and walnuts, or some roasted Brussels sprouts to balance out all that sweetness.

Storage Instructions

Refrigerate: Sweet potato casserole keeps really well in the fridge for up to 5 days when covered tightly with foil or plastic wrap. I actually think it tastes even better the next day because all those flavors have time to meld together. Just make sure it’s completely cooled before covering to avoid condensation.

Freeze: This casserole freezes like a dream for up to 3 months! You can freeze it before or after baking – just wrap it really well in plastic wrap and then foil. If you’re freezing it unbaked, add about 15-20 extra minutes to the cooking time when you’re ready to make it.

Warm Up: To bring back that fresh-from-the-air-fryer taste, cover with foil and warm it in a 350°F oven for about 15-20 minutes until heated through. If you want those marshmallows nice and toasty again, remove the foil for the last 5 minutes. You can also reheat individual portions in the microwave for about 1-2 minutes.

Preparation Time	15-20 minutes
Cooking Time	10-14 minutes
Total Time	25-34 minutes
Level of Difficulty	Easy

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 2000-2200
• Protein: 30-40 g
• Fat: 90-110 g
• Carbohydrates: 300-320 g

Ingredients

For the topping:

• 1/2 cup pecans, chopped (finely chopped, about 1/4-inch pieces)
• 1/2 cup packed brown sugar
• 1 tsp ground cinnamon (optional, enhances warm spice flavor)
• 1/2 cup all-purpose flour (I use King Arthur all-purpose flour)
• 1/2 cup white sugar
• 1/4 cup unsalted butter, cold and cubed (keeps topping crumbly)

For the sweet potato layer:

• 4 large sweet potatoes, cooked (baked, boiled, or air fried until fork-tender)
• 1 tsp vanilla extract (pure vanilla for best flavor)
• 1/2 cup pecans, roughly chopped (I prefer Libby’s selection)
• 1/2 cup white sugar
• 1/2 cup unsalted butter, melted (cooled slightly before mixing)
• 2 large eggs (room temperature for better mixing)

For serving (optional):

• 2 cups mini marshmallows (optional but recommended for that classic casserole taste)

Step 1: Prepare the Sweet Potato Base

• 4 large sweet potatoes, cooked
• 1/2 cup white sugar
• 2 large eggs, room temperature
• 1 tsp vanilla extract
• 1/2 cup unsalted butter, melted
• 1/2 cup pecans, roughly chopped

If you haven’t already cooked your sweet potatoes, bake, boil, or air fry them until they’re completely fork-tender and soft throughout.

Once cooked, let them cool just enough to handle comfortably.

In a large bowl, combine the cooked sweet potatoes, white sugar, room-temperature eggs, vanilla extract, and melted butter.

Mash everything together until you reach a smooth, creamy consistency with no large chunks remaining.

Fold in the roughly chopped pecans until evenly distributed throughout the mixture.

I like to reserve about 2 tablespoons of the pecans to sprinkle on top for extra texture and visual appeal.

Step 2: Make the Crumbly Streusel Topping

• 1/2 cup white sugar
• 1/2 cup all-purpose flour
• 1 tsp ground cinnamon
• 1/4 cup unsalted butter, cold and cubed
• 1/2 cup pecans, finely chopped

In a separate small bowl, whisk together the white sugar, all-purpose flour, and ground cinnamon.

Add the cold cubed butter and use a fork or your fingertips to work it into the dry mixture until it resembles coarse breadcrumbs with pea-sized pieces of butter still visible.

This texture is key—you want it crumbly, not paste-like.

Stir in the finely chopped pecans until incorporated.

The cold butter is what keeps this topping crumbly rather than dense, so don’t let it warm up while mixing.

Step 3: Assemble and Air Fry the Casserole

• sweet potato mixture from Step 1
• streusel topping from Step 2
• 2 cups mini marshmallows

Preheat your air fryer to 350°F.

While it heats, lightly grease a baking dish that fits comfortably in your air fryer basket.

Spread the sweet potato mixture from Step 1 evenly into the prepared dish.

Sprinkle the streusel topping from Step 2 over the sweet potato layer, breaking up any larger clumps as you go.

Top with the 2 cups of mini marshmallows, scattering them evenly across the surface—they’ll puff up and create that classic casserole appearance.

Place the dish in the preheated air fryer and cook at 350°F for 10–14 minutes, until the streusel is golden brown and the marshmallows are puffy and lightly toasted.

Let the casserole cool for 5–10 minutes before serving so it sets slightly and is easier to portion.