How to Make Sweet Potato Casserole From Scratch (and Make It Ahead)

A common starting point for a 9 by 13 inch dish that serves 6 to 8 is about 3 pounds of sweet potatoes, ½ cup (1 stick) of melted unsalted butter, ⅓ cup of brown sugar, ½ cup of milk or cream, 2 eggs, 1 teaspoon of vanilla, 1 teaspoon of cinnamon and ½ teaspoon of salt. Recipes differ on the sugar and the spices, so taste the filling before the eggs go in and adjust.

1. Roast the sweet potatoes whole until soft, then peel them (see the next section).
2. Turn the oven down to 350°F.
3. Mash the warm sweet potatoes until smooth with the butter, sugar, milk or cream, vanilla, cinnamon and salt.
4. Let the mixture cool for a few minutes, then stir in the beaten eggs so they don’t scramble.
5. Spread the filling in a greased dish and add your topping.
6. Bake uncovered for 30 to 40 minutes, until the casserole is hot all the way through and the topping is golden.

Roast them. Boiling is faster, but it adds water to the sweet potatoes, and that water ends up in the filling, which is why boiled versions usually need eggs to thicken them. Roasted sweet potatoes bring less moisture and a deeper flavor. Prick them, set them on a lined baking sheet and roast them whole at 400°F for 45 to 60 minutes, until a knife slides into the thickest part with no resistance. If you are short on time and boil them, cook them whole in their skins rather than in chunks, and drain them well before you mash. Two of our chefs also put sweet potatoes at the center of a dish. Edward Lee teaches Grilled Sweet Potatoes with creamy insides and crispy outsides in his Backyard Barbecue lesson, and Asma Khan serves a tangy Shakarkandi sweet potato salad in her Bengali Supper lesson.

Both are common, and cooks disagree about which is the traditional one, so pick the texture you want. For a streusel, mix ¾ cup of chopped pecans, ½ cup of flour, ½ cup of brown sugar and a pinch of salt, then rub in 4 tablespoons of cold butter with your fingertips until it clumps. No pecans? Walnuts work, or leave the nuts out for a plain brown sugar crumble. For marshmallows, bake the casserole on its own until it is hot, then scatter them over the top for the last 5 to 10 minutes and watch closely, because they go from toasted to burnt quickly.

Bake the casserole uncovered at 350°F for 30 to 40 minutes, until the filling is hot all the way through and a streusel topping is golden. If the topping browns too fast, cover the dish loosely with foil. Let it rest for 5 to 10 minutes before you serve it so it firms up enough to scoop. A casserole that goes into the oven cold from the refrigerator needs longer, so see the make-ahead timings below.

It is a good make-ahead dish. Spread the filling in the baking dish, cover it, and keep the topping in a separate airtight container, both in the refrigerator, for up to 2 days. Add the topping just before baking, which keeps it crisp. Take the dish out of the refrigerator about 30 minutes before it goes in the oven, and bake at 350°F for about 35 to 45 minutes, until it is hot in the center. You can also freeze it unbaked: one source says up to 2 months, thawed overnight in the refrigerator before baking.

Get leftovers into the refrigerator within two hours of cooking. USDA says leftovers keep for three to four days. To reheat, cover the dish with foil and warm it in a 350°F oven for 20 to 25 minutes, until it is steaming hot and a thermometer reads 165°F, then take the foil off for the last few minutes to crisp the topping again. Cooked casserole can also go in the freezer, where it keeps its quality best for two to three months.

If you want something with a different character from a casserole, Edward Lee’s grilled sweet potatoes and Asma Khan’s salad above both let the sweet potato take the lead. Once the casserole is in, you can fill the rest of the table from our roundups of holiday side dishes and potato side dishes, and our guide to baking the perfect potato.