If you love the gooey, buttery comfort of holiday sides, the Boston Market sweet potato casserole is the kind of dish that makes people suddenly very friendly at the dinner table.
I love this because it balances silky, whipped sweet potatoes with a crunchy, brown-sugar pecan topping and soft, toasty marshmallow textures that play off one another like a tiny symphony.
You’ll notice a warm vanilla aroma as it bakes and a sweet, slightly savory backbone from butter and a touch of salt. It’s a must-make when you want a restaurant-style casserole without the fuss.
Boston Market Sweet Potato Casserole
Equipment
- Large pot – for boiling sweet potatoes
- Mixing bowl – for mashing and combining ingredients
- 9×13 inch baking dish – to assemble and bake the casserole
- Hand mixer or potato masher – for a smooth texture
Ingredients
- 900 g 2 lb sweet potatoes, peeled and cubed
- 60 g 1/4 cup unsalted butter, melted
- 120 g 1/2 cup brown sugar, packed
- 60 ml 1/4 cup milk
- 1 large egg beaten
- 1 tsp 5 g vanilla extract
- 1/2 tsp 3 g ground cinnamon
- 1/4 tsp 1.5 g salt
- 90 g 3/4 cup pecans, chopped
- 60 g 1/3 cup all-purpose flour
- 50 g 1/4 cup brown sugar (for crumble)
- 150 g 1.25 cups mini marshmallows
Instructions
- Preheat oven to 190 C (375 F). Boil sweet potato cubes in salted water until fork-tender, about 15-20 minutes. Drain well.
- Mash potatoes until smooth with butter, brown sugar, milk, egg, vanilla, cinnamon, and salt. Taste and adjust sweetness or salt to balance flavor.
- Transfer mixture to prepared 9×13 inch dish, smoothing the top with a spatula so it bakes evenly.
- Make the crumble: stir chopped pecans, flour, brown sugar, and remaining butter until coarse crumbs form. Sprinkle evenly over sweet potato layer.
- Bake uncovered for 12 minutes, then scatter mini marshmallows across the top and bake another 3 minutes until marshmallows are puffed and golden, watching closely to prevent burning.
- Let rest 5 minutes so the casserole sets slightly. Serve warm so you get stringy marshmallow peaks and a crisp pecan crunch.
Notes
- Make-ahead: Assemble without marshmallows and refrigerate up to 24 hours; add marshmallows before the final bake.
- Pecans: Toasting pecans first deepens flavor and crunch.
- Texture: For a silkier base, pass through a ricer or use an immersion blender briefly.
The Magic of This Boston Market Sweet Potato Casserole Recipe
The first reason this Boston Market sweet potato casserole works is texture contrast. A silken sweet potato base against a crunchy pecan crumble and pillowy marshmallows creates an irresistible mouthfeel.
I find guests always comment on that interplay.
Second, the seasoning balance is key. Brown sugar and vanilla amplify the sweet potato’s natural sugars, while a pinch of salt and cinnamon prevent cloying sweetness. You’ll taste layers, not one flat sweetness.
Third, the assembly technique locks in moisture. Mashing with warm butter and adding an egg and milk yields a stable, creamy structure that holds when baked and scooped.
The topping strategy gives you both crunch and toast. Toasted pecans give nutty aromatics, and the brief final broil on marshmallows gives a restaurant-style casserole finish without overcooking the base.
Pantry Stars That Make This Boston Market Sweet Potato Sing
- 900 g (2 lb) sweet potatoes: starch and natural sugars, providing creamy body and caramelization.
- 60 g (1/4 cup) unsalted butter: fat for smooth mouthfeel and flavor transfer.
- 120 g (1/2 cup) brown sugar: sucrose and molasses add moisture and deep caramel notes.
- 60 ml (1/4 cup) milk: liquid to create a silky emulsion with fats and starches.
- 1 large egg: protein for structure and sheen when baked.
- 1 tsp (5 g) vanilla extract: volatile aromatics for sweetness perception.
- 1/2 tsp (3 g) ground cinnamon: a warm spice that complements sweet potato’s natural flavor compounds.
- 90 g (3/4 cup) pecans: toasted oil-rich nuts for crunch and Maillard flavor.
- 150 g (1.25 cups) mini marshmallows: sugar matrix that toasts and creates soft peaks.
Kitchen Tools You’ll Need
- Large pot – for boiling sweet potatoes evenly.
- Hand mixer or potato masher – to achieve the desired smoothness.
- 9×13 inch baking dish – for even baking depth and presentation.
- Mixing bowls – for mash and crumble prep.
Hands-On Magic: Building the Silky, Sugary Casserole Core
- Boil: Place peeled, cubed sweet potatoes in salted water. As they simmer, you’ll smell earthy sweetness rising from the pot; test with a fork until they’re tender but not falling apart, about 15-20 minutes.
- Drain and dry: Drain thoroughly and return to the hot pot for 1 minute to evaporate residual moisture. The surface will steam lightly – that’s good, it prevents watery mash.
- Mash: Add melted butter and start mashing. The aroma of butter blooming with sweet potato is comforting and rich. Work until mostly smooth, then add brown sugar, milk, beaten egg, vanilla, cinnamon, and salt. The mixture should feel glossy and thick.
- Taste and adjust: If it’s too sweet, add a pinch more salt; if too thick, a tablespoon of milk will loosen it. The texture should ribbon slightly when spooned.
- Assemble: Spoon into a buttered 9×13-inch dish, smoothing the top. The surface should look satiny and even, which helps the crumble adhere.
- Crumble and bake: Scatter the pecan-flour-brown sugar crumble over the surface. Bake at 190 °C (375°F) until edges bubble and crumble is golden, about 12 minutes. The kitchen will fill with toasty, nutty scents.
- Finish with marshmallows: Scatter mini marshmallows and bake briefly until puffed and lightly golden, watching closely. The final texture is pillowy marshmallow with crunchy pockets from pecans.
Chef Confidences: Crisp, Creamy, and Foolproof Finishing Moves
Toast the pecans
Toasting pecans in a dry skillet for 3-4 minutes before making the crumble intensifies nutty oils and aroma. You’ll know they’re ready when they smell fragrant and turn slightly darker.
Control marshmallow browning
For even toasting of marshmallows, switch your oven to broil for the last 1-2 minutes and stand close; they go from golden to burned very quickly. You want soft, golden peaks, not char.
Adjust sweetness with salt
If the mash tastes flat, add a quarter teaspoon of salt at a time until the flavors pop. Salt tunes sweetness and brings out vanilla and spice.
Don’t Make These Mistakes with Boston Market Sweet Potato Casserole
Overmixing the mash
Overworking sweet potatoes can make them gluey because starches break down and become pasty. Fix: stop mashing when mostly smooth; a few small lumps are fine and pleasant in texture.
Too much liquid
Adding excessive milk thins the mash and makes the casserole loose. Fix: add liquid gradually and err on the side of thicker; residual steam during baking will loosen slightly.
Burning the topping
High oven heat or broiling too long will char marshmallows. Fix: watch the final 60 seconds of broil and move the dish to a lower rack if the topping browns too fast.
Variations and Substitutions
- Swap pecans for walnuts or almonds for a different nutty profile.
- Use coconut oil instead of butter for a dairy-free option and subtle coconut flavor.
- Replace marshmallows with a streusel of oats, brown sugar, and butter for less overt sweetness.
- Stir in 50 g (1/4 cup) cream cheese into the mash for tangy richness and creamier texture.
Frequently Asked Questions
Reheat covered in a 175 °C (350°F) oven for 15-20 minutes until warmed through. Add fresh marshmallows for the last 3 minutes if desired.
Yes, omit marshmallows and increase the crumble topping proportionally, then bake until the crumble is golden for a less sweet, more textured finish.
Assemble through the crumble stage, cover, and refrigerate up to 24 hours. Add marshmallows and bake just before serving.
