Slow-Cooker Sweet Potato Casserole with Marshmallows

This slow-cooker sweet potato casserole delivers all the creamy, spiced, marshmallow-topped comfort of the classic holiday side without taking up a single inch of oven space. Cubed sweet potatoes cook low and slow with brown sugar, butter, vanilla, cinnamon, and nutmeg until they are spoon-tender, then get mashed silky smooth.

A blanket of mini marshmallows and candied pecans melts into a gooey, crunchy topping that makes every scoop irresistible. Set it and forget it, then watch it disappear at the Thanksgiving table.

Sweet potato casserole is a non-negotiable on many holiday tables, but the oven is already packed with the turkey, rolls, and pies. This version moves the whole dish to the slow cooker, where it simmers gently for a few hours and frees up valuable oven space.

The result is just as creamy and decadent as the baked version, with a golden marshmallow topping that turns glossy and caramelized. It is a hands-off way to get a beloved side dish on the table with minimal fuss.

Ingredients

Why this recipe works

The slow cooker does all the work here. Cooking the sweet potatoes on HIGH for three and a half hours allows the natural sugars to caramelize slowly while the butter and brown sugar melt into a rich, syrupy base. The low, even heat keeps the potatoes from scorching on the bottom and gives them time to become completely tender, so mashing is effortless. Because everything cooks in one pot, the flavors meld together beautifully and cleanup is a breeze.

The final fifteen minutes under the lid are what turn this into a showstopper. The mini marshmallows soften and puff into a cloud-like topping, while the candied pecans add a buttery crunch that contrasts with the creamy sweet potato base. The gentle heat of the slow cooker melts the marshmallows without burning them, so you get that iconic gooey pull with every serving. It is a simple technique that delivers a picture-perfect finish.

Notes and substitutions

Choose sweet potatoes that are firm and heavy for their size, with smooth, unblemished skin. Peel them and cut into even 1-inch cubes so they cook evenly. Brown sugar adds a deep molasses note, while the cinnamon and nutmeg give the casserole its warm holiday flavor.

Use a good-quality vanilla extract for the best taste. The candied pecans bring sweetness and crunch; if you cannot find them, toasted chopped pecans tossed with a little maple syrup work well.

A 6-quart slow cooker is ideal for this recipe because it holds the full 4 pounds of sweet potatoes without crowding. If your slow cooker is smaller, reduce the recipe proportionally.

Stir the mixture once during cooking to help the sugar and butter distribute evenly, but avoid lifting the lid too often. For a smoother mash, use a potato masher or an electric hand mixer on low speed. The marshmallows should be added only at the end so they do not dissolve into the potatoes.

• candied pecans: toasted chopped pecans tossed with a little maple syrup and brown sugar
• melted butter: unsalted butter or vegan butter
• brown sugar: coconut sugar or maple syrup (reduce liquid slightly)
• ground nutmeg: ground allspice or pumpkin pie spice

Equipment

• 6-quart slow cooker
• vegetable peeler
• chef's knife
• cutting board
• measuring cups and spoons
• wooden spoon or potato masher