Sweet Potato Casserole with Pecan Topping (Make-Ahead Thanksgiving Side)
This sweet potato casserole has a smooth, lightly sweet filling under a crunchy brown sugar and pecan topping, and you can make it two days before Thanksgiving. With the big day on 26 November, it is one of the easiest sides to cross off your list early, because it only needs 35 minutes in the oven while the turkey rests.
Why this sweet potato casserole works
- Not too sweet. The filling uses only 1/3 cup of brown sugar, because the pecan topping brings plenty of sweetness on its own. It tastes like a side dish, not a dessert.
- Crunch on top, creamy below. A simple crumble of pecans, brown sugar, flour and butter bakes into a crisp layer over the soft sweet potatoes. No marshmallows needed (see the swap below if your family loves them).
- Boiled, not roasted. Cubed sweet potatoes boil soft in about 15 to 20 minutes, which is faster than roasting them whole and keeps the oven free for other dishes.
- Built for make-ahead. You can mash and mix the filling up to 2 days ahead and keep the topping in a separate container until baking day.
What you need
For the filling:
- Sweet potatoes: 4 pounds (about 5 to 6 medium), peeled and cut into 1-inch cubes.
- Brown sugar: 1/3 cup, packed.
- Milk: 1/2 cup. Whole milk is best, but any milk works.
- Eggs: 2 large. They help the filling set so it scoops cleanly.
- Butter: 4 tablespoons, melted.
- Vanilla extract: 1 teaspoon.
- Ground cinnamon: 1/2 teaspoon.
- Salt: 1/2 teaspoon.
For the pecan topping:
- Pecans: 1 cup, chopped.
- Brown sugar: 3/4 cup, packed.
- All-purpose flour: 1/3 cup.
- Butter: 4 tablespoons, melted.
- Salt: a pinch.
How to make sweet potato casserole
- Boil the sweet potatoes. Put the cubes in a large pot, cover with cold water by about an inch and add a big pinch of salt. Bring to a boil, then simmer for 15 to 20 minutes, until a fork slides in with no resistance.
- Drain and dry. Drain well and return the cubes to the hot pot for a minute to steam off extra water. Wet sweet potatoes make a loose, watery filling.
- Heat the oven. Heat the oven to 350°F and butter a 9×13-inch baking dish (or another 3-quart dish).
- Mash and mix. Mash the sweet potatoes until smooth, using a masher or a hand mixer. Let them cool for about 10 minutes so the eggs do not scramble, then mix in the brown sugar, milk, eggs, melted butter, vanilla, cinnamon and salt.
- Fill the dish. Spread the filling evenly in the baking dish.
- Make the topping. In a small bowl, stir together the pecans, brown sugar, flour, melted butter and a pinch of salt until it looks like wet sand. Scatter it evenly over the filling.
- Bake. Bake for 30 to 35 minutes, until the topping is deep golden and the center no longer looks wet. Because the filling has eggs, it should reach 160°F in the middle if you check with a thermometer.
- Rest. Let the casserole sit for 10 minutes before serving. The topping firms up as it cools a little.
How to make it ahead
This sweet potato casserole is a good dish to get out of the way early in Thanksgiving week.
- Up to 2 days ahead: make the filling, spread it in the baking dish, cover it tightly and keep it in the fridge. Mix the topping and keep it in a separate covered container in the fridge, so it stays crumbly.
- On the day: take the dish out of the fridge 30 minutes before baking. Scatter on the topping and bake at 350°F for 40 to 45 minutes, a little longer than usual because the filling starts cold.
- Oven space: it bakes at the same temperature as many holiday sides. If you are also making our green bean casserole from scratch, both dishes can share the oven while the turkey rests. Our corn casserole also bakes at 350°F.
Swaps and variations
- Marshmallow topping: skip the pecan crumble. Bake the plain filling for 25 minutes, cover the top with mini marshmallows and bake for 5 to 10 minutes more, until they are puffed and golden. Watch closely, because they burn fast.
- Half and half: put the pecan crumble on one half of the dish and marshmallows on the other half for the last few minutes. Everyone gets their favorite.
- Nut-free: replace the pecans with old-fashioned oats in the topping for a similar crunch.
- Less sugar: leave the brown sugar out of the filling. Sweet potatoes are naturally sweet, and the topping still adds a sweet finish.
- Canned sweet potatoes: you can use two 29-ounce cans of drained, unsweetened sweet potatoes (or yams) in place of fresh. Skip the boiling step and start at step 4. Taste before adding sugar, because some canned ones come in syrup.
Storing leftovers
Get leftovers into the fridge within 2 hours of serving. Covered, they keep for 3 to 4 days. Reheat portions in the microwave or the whole dish at 350°F, covered with foil, until hot all the way through. The topping softens a little in the fridge but crisps up again in the oven. For more storage times, see the USDA page on leftovers and food safety.
You can also freeze the baked casserole, well wrapped, for up to 3 months. Thaw it in the fridge overnight before reheating.
What to serve with sweet potato casserole
Sweet potato casserole sits next to the main dish on most Thanksgiving tables. Serve it with our easy roast turkey and a spoonful of easy turkey gravy, then add something tart like homemade cranberry sauce and something green like roasted Brussels sprouts to balance the sweet. For the rest of the menu, see our full list of easy Thanksgiving side dishes.
Frequently asked questions
Can I make sweet potato casserole the day before?
Yes. Make the filling and spread it in the dish, then cover and chill it for up to 2 days. Keep the pecan topping in a separate container and add it just before baking. Bake for 40 to 45 minutes from cold.
Should I boil or roast the sweet potatoes?
Both work. Boiling cubes takes 15 to 20 minutes and is easiest. Roasting whole sweet potatoes at 400°F for 50 to 60 minutes gives a slightly deeper flavor, but takes longer and uses the oven.
Why is my sweet potato casserole watery?
Usually the sweet potatoes were not drained well. Let them steam dry in the hot pot for a minute after draining, and measure the milk instead of adding extra.
Are sweet potatoes and yams the same?
In most US stores, orange sweet potatoes are often labeled “yams”, and either one works here. True yams are a different, drier root you are unlikely to find in a regular supermarket.
Sweet Potato Casserole with Pecan Topping
Ingredients
Method
- Put the sweet potato cubes in a large pot, cover with cold water by about an inch and add a big pinch of salt. Bring to a boil, then simmer for 15 to 20 minutes, until very tender.
- Drain well and return the cubes to the hot pot for 1 minute to steam off extra water.
- Heat the oven to 350°F and butter a 9×13-inch (3-quart) baking dish.
- Mash the sweet potatoes until smooth. Cool for about 10 minutes, then mix in 1/3 cup brown sugar, the milk, eggs, 4 tablespoons melted butter, vanilla, cinnamon and 1/2 teaspoon salt.
- Spread the filling evenly in the baking dish.
- Stir together the pecans, 3/4 cup brown sugar, flour, 4 tablespoons melted butter and a pinch of salt until crumbly. Scatter over the filling.
- Bake for 30 to 35 minutes, until the topping is deep golden and the center is set (160°F). Rest for 10 minutes before serving.
Notes
- Make ahead: chill the filling in the dish and the topping in a separate container for up to 2 days. Add the topping and bake for 40 to 45 minutes from cold.
- Marshmallow version: bake the plain filling 25 minutes, top with mini marshmallows and bake 5 to 10 minutes more.
- Leftovers keep 3 to 4 days in the fridge.
This recipe was developed with the help of AI tools and reviewed before publishing. It may not have been independently kitchen-tested — use your judgment, check for allergens, and cook to safe temperatures. See our AI Content Disclosure. Spotted an issue? Tell us.
