Sweet Potato Casserole with Pecans & Marshmallows

Roast five sweet potatoes till the skin wrinkles and a knife slides through like butter. That’s where this starts. Everything after that is basically assembly—sugar, vanilla, eggs, milk, and browned butter stirred into the mashed flesh. Then pecans and crushed pineapple folded in gently. The topping’s crumbly. Brown sugar, flour, softened butter, more pecans. Marshmallows go in twice—half buried under the crumble, the rest scattered on top right before the final bake. That’s the whole thing.

Why You’ll Love This Sweet Potato Casserole

Tastes like Thanksgiving on a normal Tuesday. Comfort food that actually fills the table—pecan crunch, marshmallow melt, pineapple sweetness underneath it all. Takes two-plus hours total if you count roasting time, but most of that is the oven doing the work while you sit. Holiday vibes without feeling like you spent all day cooking. Stays warm for a while after it comes out. Works cold the next day, reheats fine in a 300-degree oven for ten minutes. Side dish that people actually want seconds of.

What You Need for Sweet Potato Casserole

Five large sweet potatoes—washed, pricked all over with a fork. One cup granulated sugar. A tablespoon of vanilla extract. Two eggs. One cup evaporated milk—or coconut milk if you want something richer. Six tablespoons of browned butter, melted. Three-quarters cup brown sugar. One-third cup all-purpose flour. Six tablespoons of softened unsalted butter—different from the browned butter. One cup chopped pecans. One cup crushed pineapple, drained well. Two cups mini marshmallows, kept separate. Nonstick cooking spray. That’s it.

How to Roast and Prep Sweet Potatoes for Casserole

Heat the oven to 355. Line a baking sheet with foil, lay the pricked potatoes on it flat. Roast for 55 to 65 minutes—you’re looking for the skin to wrinkle slightly and a knife to pierce all the way through with zero resistance. Not soft on the outside while the center fights back. All the way through. Cool them till you can handle them without cursing. Peel the skins off—a paring knife works, but honestly rubbing them with a paper towel is faster. The skin comes off if it’s roasted right.

Spray a two-quart casserole dish with cooking spray. Actual spray, not a light mist. You’ll thank yourself later when you’re trying to get this thing out of the dish.

How to Build the Sweet Potato Mixture

Mash the peeled potatoes in a large bowl. Mixer or masher—doesn’t matter. Some rough chunks are fine. Actually better. Gives it texture instead of baby food. Stir in the granulated sugar, vanilla, eggs, and evaporated milk. Fold in the browned butter gently. Pour in the drained pineapple without overmixing it to death. You want the fruit distributed, not obliterated.

Spread half the mini marshmallows across the bottom of the casserole dish. Just lay them on top of the sweet potato mixture. They’ll sink a little. That’s the point.

Building the Pecan Topping and Final Assembly

Fork brown sugar, flour, and softened butter together in a bowl till it looks like damp sand. Not mixed smooth. Crumbly. Fold in the chopped pecans evenly. Don’t overwork it or you’ll lose the texture. Spoon this crumb mixture over the marshmallows in a single layer. It’ll hide most of them but you’ll see the texture through the gaps.

Bake for 28 to 32 minutes. Watch the edges—they’ll start bubbling. The topping turns golden. This is when you can pull it out, scatter the remaining marshmallows on top, and put it back in for 8 to 12 more minutes. Marshmallows puff up, melt into the gaps, turn light toasty brown. Listen for faint crackling. Watch the whole time once they’re on top. Orange scorch marks happen fast.

Pull it out. Let it rest for at least ten minutes. The topping hardens slightly but stays soft underneath. Slice with a serrated knife so you don’t destroy the edges.

Sweet Potato Casserole with Pecans & Marshmallows

By Emma

Prep:

85 min

Cook:

42 min

Total:

127 min

Servings:

12 servings

Ingredients

• 5 large sweet potatoes, washed and pricked
• 1 cup granulated sugar
• 1 tablespoon vanilla extract
• 2 large eggs
• 1 cup evaporated milk or substitute coconut milk
• 6 tablespoons browned butter, melted
• 3/4 cup brown sugar
• 1/3 cup all-purpose flour
• 6 tablespoons softened unsalted butter
• 1 cup chopped pecans
• 1 cup crushed pineapple, drained
• 2 cups mini marshmallows, divided
• Nonstick cooking spray

Method

1. 1 Heat oven to 355°F. Line baking sheet with foil. Place washed, pricked sweet potatoes on foil. Roast 55-65 minutes. Done when knife pierces smoothly with no resistance, skin wrinkles slightly. Cool till handheld. Peel off skins, best with a paring knife or rub with paper towel to save time.
2. 2 Spray 2-quart casserole dish liberally with cooking spray. Avoid oil slicks, extra spray helps release sticky mashed mix later.
3. 3 Mash peeled potatoes in large bowl with masher or mixer. Rough chunks OK — gives texture. Stir in sugar, vanilla, eggs, evaporated milk (or coconut for tropical depth). Fold in browned butter, pour in crushed pineapple gently to avoid overmixing.
4. 4 For topping: fork together brown sugar, flour, and softened butter till crumbly like damp sand. Fold in pecans evenly distributed. No overmixing here—keep crumbs intact.
5. 5 Spread half mini marshmallows evenly atop sweet potato mix. Spoon crumb topping over marshmallows in a layer that hides them but shows texture.
6. 6 Bake 28 to 32 minutes. Watch edges bubbling and topping turning golden. Peek inside if unsure—topping should be set but not burned. Pull out carefully.
7. 7 Scatter remaining marshmallows on top. Bake additional 8 to 12 minutes until marshmallows puff, melt, and turn a light toasty brown. Listen for faint crackling as marshmallows toast. Watch constantly to prevent orange scorch marks.
8. 8 Rest at least 10 minutes before serving. Cool slightly to let flavors meld. Topping hardens a bit but stays gooey beneath. Slice with serrated knife for clean edges.

Nutritional information

Calories

424

Protein

5g

Carbs

58g

Fat

20g

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Frequently Asked Questions About Baked Sweet Potato Casserole

Can I prep this the day before and bake it on Thanksgiving? Yeah. Assemble everything except the marshmallows, cover with foil, stick it in the fridge overnight. Add a few minutes to the first bake if it’s cold when it goes in. Then marshmallows on top right before the second bake. Same timing.

Do I have to use browned butter? Not technically. Regular melted butter works. But browned butter has something going on—nuttier, more depth. Worth it if you have five minutes to brown it on the stove.

What if I don’t have crushed pineapple? Haven’t tried it without. But fresh pineapple drained really well might work. Or skip it. The casserole still works. Just less tropical sweetness. Might need more vanilla to compensate. Or not.

Can I make this in the microwave instead of roasting? Roasting in oven takes 55 to 65 minutes but the flavor’s way better. Microwaving’s faster but the texture gets watery. Not worth the time saved.

Should I use canned or fresh sweet potatoes? Roasted. Always. Canned tastes different. Too soft, too sweet already. The roasting caramelizes them a bit.

How do I store leftovers? Cover and refrigerate up to four days. Reheats in a 300-degree oven for about ten minutes. Or eat it cold. Works either way. Texture changes—softer when cold, which some people prefer.

What’s the difference between sweet potato and regular potato casserole? Different flavor entirely. Sweet potato’s sweeter, more dessert-like. Regular potato casserole is savory. This one’s got the pecan topping, marshmallows, pineapple. It’s in a different category. Side dish that tastes like a holiday.