Southern Sweet Potato Casserole Recipe for a Crowd

I make this southern sweet potato casserole every Thanksgiving and it disappears before anything else on the table. Silky mashed sweet potatoes topped with a buttery pecan streusel — it bakes in 30 minutes and can be fully assembled the day before. One dish feeds a crowd with zero stress.

Why This Southern Sweet Potato Casserole Works

The sweet potato base is smooth and lightly sweetened. Brown sugar, butter, and a splash of half-and-half fold in after mashing — the result is almost custardy when it bakes. It does not taste like a dessert. It tastes like the best part of the meal.

The pecan streusel topping is the southern difference. Brown sugar, cold butter, and chopped pecans press into a crumbly, caramelized crust in the oven. It stays crunchy even as the casserole sits on the table for an hour.

This casserole holds perfectly. I assemble it the night before, cover it, and refrigerate overnight. Pull it out 30 minutes before baking and it goes straight into the oven — no adjustments needed.

Ingredients

• 4 cups sweet potatoes, cooked and mashed (about 3-4 medium sweet potatoes)
• 1/3 cup butter, melted
• 3/4 cup brown sugar, divided
• 1/3 cup half-and-half
• 2 large eggs, beaten
• 2 teaspoons vanilla extract
• 1/2 teaspoon salt
• 1/3 cup all-purpose flour
• 1 cup pecans, roughly chopped
• 3 tablespoons cold butter, cubed
• 1/2 teaspoon cinnamon

What You Need for Southern Sweet Potato Casserole

Sweet potatoes — boil or roast them until completely soft. Roasted sweet potatoes have a deeper, more caramelized flavor. Boiled are faster. Either way, mash while hot for the smoothest texture.

Eggs — beaten and folded into the sweet potato base. They bind the filling and give it that slightly custardy set when baked. Do not skip them — without eggs the casserole stays loose and will not hold when scooped.

Half-and-half — adds creaminess without making the filling too liquid. Heavy cream makes it too rich. Whole milk works but gives a slightly looser texture.

Cold butter for the streusel — must be cold. Warm butter melts into the flour instead of creating crumbles. Cut it into small cubes and work it into the flour and sugar with your fingers until pea-sized pieces form.

Pecans — the southern signature. They toast in the oven as the casserole bakes and turn deep golden and crunchy. Walnuts work as a substitute but lack the same buttery flavor that pecans bring.

Vanilla extract — use real vanilla, not imitation. The warm, floral notes round out the sweetness of the brown sugar and sweet potato.

How to Make Southern Sweet Potato Casserole

1. Preheat oven to 350F (175C). Grease a 9×13-inch baking dish.
2. Peel and cook the sweet potatoes: boil in salted water for 15 minutes until fork-tender, then drain well.
3. Mash the hot sweet potatoes until smooth. No lumps.
4. Stir in the melted butter, 1/2 cup of the brown sugar, half-and-half, beaten eggs, vanilla extract, and salt. Mix until fully combined.
5. Spread the sweet potato mixture evenly into the prepared baking dish.
6. Make the pecan streusel: combine the flour, remaining 1/4 cup brown sugar, cinnamon, and cubed cold butter in a bowl. Work together with your fingers until crumbly and pea-sized. Stir in the chopped pecans.
7. Sprinkle the pecan streusel evenly over the sweet potato layer.
8. Bake uncovered for 30 minutes until the topping is golden brown and the filling is set.
9. Let rest for 10 minutes before serving.

Southern Sweet Potato Casserole Variations

Sweet Potato Casserole With Marshmallows

Skip the pecan streusel. Spread the sweet potato base in the baking dish, then cover the entire top with a single layer of mini marshmallows. Bake at 350F for 25 minutes until the marshmallows are golden and toasted. This version is softer and sweeter — kids love it.

Southern Sweet Potato Casserole With Both Toppings

Make the pecan streusel as directed. Cover half the casserole with streusel and the other half with mini marshmallows. The compromise move for a crowd that cannot agree — both sides of the table win.

Crockpot Sweet Potato Casserole

Spread the sweet potato base into a greased slow cooker insert. Add the pecan streusel on top. Cook on high for 2.5 hours or low for 4 hours. The streusel will not get as crunchy as oven-baked but the filling is just as good.

Dairy-Free Sweet Potato Casserole

Swap the half-and-half for full-fat coconut milk and use dairy-free butter throughout. The coconut flavor is subtle and pairs well with the brown sugar and vanilla. The texture is nearly identical to the original.

Tips for the Best Southern Sweet Potato Casserole

• I roast the sweet potatoes at 400F (200C) for 45 minutes instead of boiling. The flavor concentrates and the flesh is drier — the casserole filling sets up firmer.
• Drain boiled sweet potatoes very well. Excess water makes the filling runny and prevents the eggs from setting properly.
• Keep the streusel butter cold until the last minute. I cut the butter and put it back in the freezer for 10 minutes before working it in.
• Do not overbake. The filling should still have a slight jiggle in the center when you pull it out — it sets up as it cools.
• Make it the day before. The flavors deepen overnight and the morning-of prep is just preheating the oven.

Make Ahead & Storage

This southern sweet potato casserole is ideal for making ahead. Assemble the whole dish including the streusel topping, cover tightly with plastic wrap, and refrigerate up to 24 hours. Remove from the fridge 30 minutes before baking and add 5 extra minutes to the bake time since it starts cold.

Leftovers keep in the fridge for up to 4 days covered tightly. Reheat individual portions in the microwave for 90 seconds. Reheat the whole dish covered with foil at 300F (150C) for 20 minutes. The pecan topping softens in the fridge but crisps back up in the oven.

Common Questions

Can I use canned sweet potatoes instead of fresh?

Yes. Drain canned sweet potatoes very well and pat dry before mashing. They are softer and sweeter than fresh — reduce the brown sugar in the filling by 2 tablespoons to compensate. The texture will be slightly looser but the flavor is still good.

How do I know when sweet potato casserole is done?

The pecan topping should be deep golden brown and the edges of the filling should be set. The center can still jiggle slightly — it firms up as it cools. A toothpick inserted into the center should come out clean after the 10-minute rest.

Can I make southern sweet potato casserole gluten-free?

Yes. Swap the all-purpose flour in the streusel for a 1:1 gluten-free flour blend or certified gluten-free oat flour. The texture is nearly identical. Confirm your brown sugar is gluten-free as well — most brands are, but cross-contamination labeling varies.

How far in advance can I make sweet potato casserole?

Assemble up to 24 hours ahead and refrigerate unbaked. For longer prep, bake the sweet potato filling (without the streusel) and freeze for up to 1 month. Thaw overnight in the fridge, add the fresh streusel topping, and bake as directed.

What goes with southern sweet potato casserole?

A classic Thanksgiving side alongside roast turkey, green bean casserole, mashed potatoes, and cornbread dressing. For everyday dinners, it pairs well with baked ham, pork roast, or grilled chicken thighs. The sweetness contrasts with savory mains perfectly.

This southern sweet potato casserole is the dish I am always asked to bring. Save this recipe before the holidays and make it the day before — you will not regret it.