Sweet Potato Casserole with Pecan Streusel Topping

Name: Sweet Potato Casserole with Pecan Streusel Topping
Prep time: 30 min
Cook time: 1 h 40 min
Total time: 2 h 10 min
Yield: 10 servings
Cuisine: Southern
Ingredients: 3 lb (about 4 medium) (1360 g) sweet potatoes, scrubbed and left whole, skins on; 4 tablespoons (57 g) unsalted butter, melted and slightly cooled; ⅓ cup, packed (73 g) light brown sugar; 2 large (100 g) large eggs, at room temperature, lightly beaten; ½ cup (120 ml) whole milk, at room temperature; 2 teaspoons (10 ml) pure vanilla extract; 1 teaspoon (3 g) ground cinnamon; ¼ teaspoon (½ g) freshly grated or ground nutmeg; ¾ teaspoon (4½ g) fine sea salt; 1 cup (100 g) pecan halves, coarsely chopped into pieces about ¼ inch (6 mm); ½ cup, packed (110 g) light brown sugar; ⅓ cup (42 g) all-purpose flour; ¼ teaspoon (1½ g) fine sea salt; 4 tablespoons (57 g) unsalted butter, cold, cut into ½-inch (1 cm) cubes

From the MyKitchenBank Kitchen

Roasting the sweet potatoes whole concentrates their sweetness and keeps the filling fluffy instead of watery. A silky, lightly spiced mash is topped with a buttery, crunchy brown sugar pecan streusel. It's the make-ahead side dish that belongs on every holiday table.

Prep: 30 min
Cook: 1 hr 40 min
Wait: 25 min
Total: 2 hr 35 min
Makes: 1 (9×13-inch) casserole, 10 generous servings

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Ingredients

10 servings

For the filling
3 lb (about 4 medium) (1360 g) sweet potatoes, scrubbed and left whole, skins on
4 tablespoons (57 g) unsalted butter, melted and slightly cooled
⅓ cup, packed (73 g) light brown sugar
2 large (100 g) large eggs, at room temperature, lightly beaten
½ cup (120 ml) whole milk, at room temperature
2 teaspoons (10 ml) pure vanilla extract
1 teaspoon (3 g) ground cinnamon
¼ teaspoon (0.5 g) freshly grated or ground nutmeg
¾ teaspoon (4.5 g) fine sea salt
For the pecan topping
1 cup (100 g) pecan halves, coarsely chopped into pieces about ¼ inch (6 mm)
½ cup, packed (110 g) light brown sugar
⅓ cup (42 g) all-purpose flour
¼ teaspoon (1.5 g) fine sea salt
4 tablespoons (57 g) unsalted butter, cold, cut into ½-inch (1 cm) cubes

Equipment (7)

9×13-inch (23×33 cm) baking dish (3-quart / 3 L)
Rimmed baking sheet lined with parchment or foil
Large mixing bowl
Potato masher or hand mixer
Medium mixing bowl
Instant-read thermometer
Fork and sharp knife

Steps

Before you start

Set out the eggs and milk 30 minutes ahead so they mix smoothly into the warm sweet potatoes and don't cool the filling down.
Cut the topping butter into cubes and keep it in the fridge until you need it. Cold butter gives you a crumbly streusel instead of a greasy paste.
Choose sweet potatoes of similar size (about 8 oz / 225 g each) so they roast evenly.
Plan for about 2½ hours start to finish. Most of that is hands-off oven time.

1
Roast the sweet potatoesOven 400°F / 205°C
- Position a rack in the center of the oven and heat to 400°F (200°C).
- Line a rimmed baking sheet with parchment or foil.
- Prick each scrubbed sweet potato 5–6 times with a fork and set them on the sheet with space between them.
- Roast for 50–60 minutes, until the skins are wrinkled and a knife slides into the thickest part with no resistance.
- Some syrupy juices will leak onto the pan.
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Ready when: Skins are wrinkled and a knife meets no resistance at the thickest part
Tip: Line the pan. The leaked sugars burn on and are very hard to scrub off.
2
Cool the potatoesOven 350°F / 175°C
- Remove the baking sheet from the oven and let the sweet potatoes cool for 15 minutes, until you can handle them comfortably.
- Reduce the oven temperature to 350°F (175°C).
- While they cool, butter or spray a 9×13-inch baking dish.
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Ready when: Potatoes are warm, not scalding, to the touch
Tip: Don't let them cool completely. Warm potatoes mash smoothly and blend easily with the butter.
3
Peel and mash
- Slip the skins off the warm sweet potatoes.
- They should peel away easily.
- Put the flesh in a large bowl (you should have about 4 cups / 1 kg) and mash with a potato masher or hand mixer on low until mostly smooth.
- A few small lumps are fine.
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Ready when: Mash is mostly smooth with no large chunks and no stringy fibers
Tip: If you find tough, stringy fibers, pull them out. A hand mixer tends to wind them around the beaters, so use a masher if your potatoes are stringy.
4
Mix the filling
- Add the melted butter, ⅓ cup (73 g) brown sugar, milk, vanilla, cinnamon, nutmeg, and ¾ teaspoon salt to the mash and stir until combined.
- Add the beaten eggs and stir for about 30 seconds, until the mixture is uniform, glossy, and thick but spoonable.
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Ready when: Filling is uniform in color with no streaks of egg
Tip: Add the eggs last, once the mash has cooled a bit. Very hot mash can scramble them.
5
Fill the dish
- Scrape the filling into the prepared 9×13-inch dish and spread it into an even layer about 1½ inches (4 cm) thick, smoothing the top with a spatula.
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Ready when: Surface is level all the way to the corners
6
Make the streusel
- In a medium bowl, whisk the chopped pecans, ½ cup (110 g) brown sugar, flour, and ¼ teaspoon salt.
- Add the cold butter cubes and rub them in with your fingertips, pinching and squeezing, for 1–2 minutes, until the mixture forms moist, clumpy crumbs with some pea-sized pieces of butter still visible.
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Ready when: Mixture holds together in clumps when squeezed, with pea-sized butter bits
Tip: If your kitchen is warm, chill the streusel for 10 minutes so the butter stays solid.
7
Bake the fillingOven 350°F / 175°C
- Bake the uncovered filling on the center rack at 350°F (175°C) for 25 minutes.
- This sets the eggs so the streusel won't sink into the filling.
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Ready when: Edges look set and the surface is slightly dry, though the center still jiggles a little
8
Add topping and finishOven 350°F / 175°C
- Remove the dish from the oven and scatter the streusel evenly over the top, breaking up any large clumps and covering all the way to the edges.
- Return the dish to the oven for 20–25 minutes at 350°F (175°C), until the topping is deep golden brown and smells toasty, and the filling bubbles lightly around the edges.
- A thermometer in the center should read 160°F (71°C).
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Ready when: Topping is deep golden brown, edges bubble, and center reads 160°F (71°C)
Tip: If the pecans darken too fast, tent the dish loosely with foil for the last 10 minutes.
9
Rest and serve
- Set the casserole on a wire rack and let it rest for 10 minutes.
- The filling firms up so it scoops cleanly and the molten sugar in the topping cools to a crisp crunch.
- Serve warm.
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Ready when: Topping is crisp and the filling holds its shape when scooped

Good to know

Tips

Roast the potatoes instead of boiling them. Boiling adds water, which makes the filling soggy and dilutes the flavor.
Measure the cooked mash if your potatoes are unusually large or small. You want about 4 cups (1 kg) for a 9×13-inch dish.
Taste the mash before adding the eggs. If your potatoes are very sweet, add another pinch of salt. If they're mild, add 1–2 tablespoons more brown sugar.
Use a thermometer rather than guessing. 160°F (71°C) in the center means the eggs are safely cooked and the filling is set.

Make ahead

"Roast, mash, and mix the filling up to 2 days ahead. Spread it in the dish, cover tightly, and refrigerate. Keep the streusel in a separate airtight container in the fridge. When ready, let the dish sit at room temperature for 30 minutes, then bake at 350°F (175°C) for 30 minutes, add the topping, and bake 20–25 minutes more until it reaches 160°F (71°C) in the center."

Storage & reheating

"Cool completely, then cover and refrigerate for up to 4 days. Freeze for up to 2 months, wrapped tightly in plastic and foil. The topping will soften with freezing. Thaw overnight in the fridge. Reheat covered with foil at 350°F (175°C) for 20–30 minutes (about 40 minutes from frozen-thawed in a deep dish), then uncover for the last 5–10 minutes to re-crisp the topping. Don't leave it at room temperature for more than 2 hours."

Substitutions

pecan halves → walnuts. Use the same weight, chopped. Toast them first for a deeper flavor. For a nut-free version, use ½ cup old-fashioned oats plus ½ cup extra flour-and-sugar crumbs.
whole milk → heavy cream or full-fat oat milk. Cream gives a richer, denser filling. Oat milk works well for a dairy-light version.
light brown sugar → pure maple syrup. Use ¼ cup (60 ml) in place of the ⅓ cup brown sugar. The filling will be slightly looser but still sets.
unsalted butter → vegan butter sticks. Keep them cold and cubed, and the streusel will behave the same.