Introduction

This Best Old Fashioned Sweet Potato Casserole is a comforting side dish that combines creamy sweet potatoes with a crunchy pecan topping and golden toasted marshmallows. Perfect for holiday gatherings or any time you crave a classic Southern-inspired treat.

A close-up shot of a sweet potato casserole in a white rectangular dish, showing three distinct layers: a bottom layer of smooth, bright orange mashed sweet potatoes, topped with a middle layer of small chopped pecans scattered unevenly, and a final top layer of white marshmallows toasted to a golden brown with some darker charred spots, puffed up and closely packed together. The image is set on a white marbled textured surface, with soft natural light highlighting the textures and colors. Photo taken with an iphone --ar 4:5 --v 7

Ingredients

2 1/2 lb sweet potatoes (peeled and cut into 1-inch pieces)
1/2 tsp vanilla extract (pure vanilla for best flavor)
1/4 cup unsalted butter (I like Kerrygold for richness)
1 1/2 tsp salt
1/4 cup pecans (finely chopped)
1/4 cup brown sugar (firmly packed for best moisture)
2 cups mini marshmallows (optional but recommended for that classic casserole texture)
1/4 cup pecans (finely chopped, adds nice crunch)
Nonstick cooking spray

Instructions

Step 1: Preheat your oven to 375°F and generously spray a 9×13 inch baking dish with nonstick cooking spray, coating the bottom and sides evenly to prevent sticking and make cleanup easier.
Step 2: Place the peeled sweet potatoes cut into 1-inch pieces in a large pot, cover with cold water, and bring to a boil over high heat. Cook for 15-20 minutes until the potatoes are fork-tender. Drain well and let cool for about 5 minutes to handle easily without breaking apart when mashing.
Step 3: Transfer the cooled sweet potatoes to a large mixing bowl. Add brown sugar, unsalted butter, salt, and vanilla extract. Mash the mixture until slightly chunky for better texture. Fold in 1/4 cup of finely chopped pecans evenly throughout.
Step 4: Spread the sweet potato mixture evenly into the prepared baking dish, smoothing the top with a spatula. Sprinkle the remaining 1/4 cup of chopped pecans over the top, then arrange mini marshmallows in a single layer with small gaps to allow puffing and browning while baking.
Step 5: Bake the casserole in the preheated oven for 20 minutes, or until the marshmallows are puffed and golden brown. Watch closely during the last few minutes to avoid burning. Let the casserole rest for 5 minutes before serving to set slightly and make portioning easier.

Tips & Variations

For a nut-free version, omit the pecans and use crushed graham crackers or toasted oats for a crunchy topping.
Sweet potatoes can be roasted instead of boiled for a deeper flavor; simply roast whole sweet potatoes at 400°F until tender, then peel and mash.
Use pure maple syrup or honey instead of brown sugar for a different sweetness profile.
If you prefer a smoother texture, mash the sweet potatoes thoroughly or blend with a hand mixer before adding pecans.

Storage

Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat gently in the oven at 325°F until warmed through, or use a microwave in short bursts to prevent marshmallows from becoming chewy. The casserole can also be prepared a day ahead and baked just before serving for convenience.

How to Serve

A white rectangular casserole dish filled with three visible layers: the bottom layer is bright orange mashed sweet potato, topped with a middle layer of creamy, slightly textured off-white mashed potatoes or similar, and finished with a top layer of toasted marshmallows that are golden brown on top with some melted, gooey parts. Scattered among the marshmallows are chopped pecans adding a rough texture and dark brown color contrast. The dish is placed on a white marbled surface, showing the mix of soft and crunchy textures clearly. Photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I make this casserole vegan?

Yes, substitute the butter with a plant-based alternative and use dairy-free marshmallows to make the casserole vegan-friendly.

Do I have to use marshmallows?

Marshmallows add a classic sweet, fluffy topping, but you can omit them if you prefer a less sweet casserole or substitute with a streusel topping for a different texture.