Slow-Cooker Sweet Potato Marshmallow Pecan Bake

This slow-cooker sweet potato marshmallow pecan bake turns a classic holiday side into a dessert-worthy treat. The sweet potatoes are whipped into a silky soufflé with brown butter, vanilla, and cinnamon, then topped with a crunchy brown sugar pecan streusel.

After a few hours in the Crockpot, the streusel caramelizes and the marshmallows melt into gooey pockets of sweetness. It's a dump-and-go recipe that frees up oven space and delivers all the comforting flavors of a traditional sweet potato casserole with minimal effort.

Sweet potato casserole is a beloved holiday staple, but this version takes it straight to the slow cooker for a hands-off, stress-free dessert. The sweet potatoes are boiled and whipped into a light, fluffy soufflé with butter, brown sugar, and warm spices.

A pecan streusel is sprinkled on top and slow-cooked until it turns into a crackly, caramelized crust. Just before serving, mini marshmallows are melted over the top for that classic gooey finish. Serve it warm as a dessert or a sweet side dish—either way, it's a crowd-pleaser.

Ingredients

Why this recipe works

Slow-cooking the casserole on HIGH for 2.5 hours allows the pecan streusel to caramelize slowly without burning, developing a deep, nutty flavor that complements the sweet potatoes. The gentle, even heat of the Crockpot also keeps the sweet potato soufflé moist and creamy, preventing it from drying out or becoming grainy. This method mimics a low oven bake but with far less attention needed.

The whipped sweet potato base is key to the soufflé-like texture. Beating the hot potatoes with butter, sugar, and eggs incorporates air, making the mixture light and fluffy.

The eggs help set the structure as it cooks, giving the casserole a custard-like consistency that holds its shape when scooped. The combination of textures—silky base, crunchy streusel, and gooey marshmallows—creates a truly irresistible dessert.

Notes and substitutions

Choose sweet potatoes that are firm and evenly shaped for even cooking. Orange-fleshed varieties like Beauregard or Jewel work best for their sweetness and creamy texture. If you prefer a less sweet casserole, reduce the brown sugar to 1/3 cup, but note that the streusel will be less caramelized. For a deeper flavor, use dark brown sugar instead of light.

This recipe uses a 6-quart slow cooker; if using a smaller one, reduce the sweet potatoes to 2 pounds and adjust the cooking time. An electric mixer is ideal for achieving a fluffy soufflé, but a potato masher works in a pinch—just expect a slightly denser texture.

The streusel can be mixed ahead and stored in the fridge for up to 3 days. Mini marshmallows are preferred for even melting, but large marshmallows cut into quarters also work.

• unsalted butter: salted butter (reduce added salt elsewhere) or vegan butter for a dairy-free option
• chopped pecans: walnuts or a mix of pecans and walnuts
• mini marshmallows: regular marshmallows cut into quarters or vegan marshmallows
• light brown sugar: dark brown sugar for a deeper molasses flavor

Equipment

• 6-quart slow cooker
• Mixing bowls
• Electric mixer or potato masher
• Rubber spatula
• Measuring cups and spoons